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Garage => Mechanicals => Topic started by: ckamila on 30 January 2012, 08:43 PM

Title: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 30 January 2012, 08:43 PM
I was going off topic on my previous thread troubleshooting a vacuum related shutdown issue which was traced to the defrost pod under the dash. http://forum.w116.org/mechanicals/removing-the-ccu-1980-300sd-engine-shutdown-problem/ (http://forum.w116.org/mechanicals/removing-the-ccu-1980-300sd-engine-shutdown-problem/) But having dived into the climate control system i wanted to bring her back as best i could with a little (or a lot) of assistance along the way.

Heater box/evaporator removal - currently need to disconnect a/c lines at expansion valve, remove right side heater hose which is giving me fits and remove the last mounting bolts. I was able to disconnect the left hose with the help of my 13 year old son - him holding brass/copper tubing inside car while I was pulling/prying from the outside. How can such a small hose be SO difficult to remove from the tubing. I must be doing something wrong? the right side has even less room to maneuver heater hose but an easier grasp of the tubing. So i need a beefier helper or different technique?


(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/CIMG1016a.jpg)
Most everything out of the way and tagged where i thought necessary.
Think i still know where everything goes?

Chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 31 January 2012, 10:04 AM
Amazing!  I removed my expansion valve with regular wrenches but crow foot wrenches would have made the job easier. Pulling the round corrugated duct that runs from the center "stack" to the window vents made it easier but it looks like it may be out of yours already.

This will give you a chance to clean the evaporator and heater core as well as install a new expansion valve.

You may want to consider upgrading the AC hoses to modern barrier type if you plan on going with R134a.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 31 January 2012, 01:31 PM
Hi Jon - Not having done this before i am following the service manual and just removing things in my way including heater vent tubes. Maybe i will invest in a few crow feet wrenches too.

On the right side heater hose - access by way of removing grill below wipers - What is the best method for removal? It appears to be glued in place. The heater hoses appear inexpensive...should they be replaced or leaved if not cracked?


Left heater hose disconnected
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/CIMG1018.jpg)


Right hose still attached
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/CIMG1017.jpg)


Right side of heater box with tube causing holdup
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/CIMG1019.jpg)


Expansion valve ready to disconnect
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/CIMG1022.jpg)


Chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 31 January 2012, 05:12 PM
Looks like a PITA...  I see where you have removed the blower assembly.

Maybe try some penetrating lubricant around the metal tube and a blunt screwdriver worked between the metal tube and hose.  If there's even room for that...

The expansion valve is tough because you must work 2 wrenches in there in order to hold the evaporator tubing and prevent any kinking or breaking of the tubes. There is also the little equilization tube to deal with.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 31 January 2012, 07:13 PM
Don't you just love it when something clicks in your head - mine usually clicks in a little slower than it should  ::)

My previous post "maybe it's glued in place" was it. IT WAS GLUED or rather melted to the tubing. Grabbed a pair of vice grips and just gave the hose a little turn to the left and then to the right and i heard the rubber snap free. Took about 30 seconds including grabbing the tool. Can't believe how much time and effort wasted in trying to pull the hoses form the tubing. No matter how much i pulled it would not pull free. Good thing this is a hobby and not a profession!

Onwards and inwards to the expansion valve!

Chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: TJ 450 on 01 February 2012, 05:20 AM
Yes, the hoses often need to be twisted to remove. Some of them are almost impossible to remove.

Tim
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 01 February 2012, 01:31 PM
1980sdga - Jon, talk to me about the 

You may want to consider upgrading the AC hoses to modern barrier type if you plan on going with R134a.

Costs? Benefit over current (original) hose?

Chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 01 February 2012, 05:28 PM
If you're going to convert to r134a then it's a good idea to replace the hose.  The old hoses worked fine with r12 but r134a will seep through the rubber and you'll be recharging the system more often.  Barrier hose has a liner that keeps r134a in the system. If you are sticking with r12 (Which is hard to find, expensive, most AC shops won't use it, etc.)  then you may be OK with the old hose.

An AC shop could probably do it using your fittings with new ferrels.  Plus you're going to have the expansion valve out anyway and you are pretty deep in it now  ;D
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: koan on 01 February 2012, 11:16 PM
If you're going to convert to r134a then it's a good idea to replace the hose.  The old hoses worked fine with r12 but r134a will seep through the rubber

Is that really the case?

It was suggested when R134A was introduced a lot of new bits would be required but in practice R12 bits work with R134A just fine, only in odd cases are any changes required and that's usually when the R12 system is only just cutting it.

Hoses are an example, theory has it that the smaller R134A molecules will seep through non barrier rubber hoses, but in practice an old oil soaked R12 A/C hose is impermeable to R134A.

koan
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 02 February 2012, 06:26 AM
Good input Koan!  I had never touched an AC system before last summer so most of my advise should be tempered with that in consideration  ;D

I believe the barrier hose was mandated by the EPA to address global warming (Or was it cooling back then  ???) rather than AC performance so messing with hoses may be overkill.  My AC was working fine on r134a before my compressor went south. My old hoses looked OK. 
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 02 February 2012, 11:25 AM
Koan and 1980sdga - Gentlemen, please keep the lively discussion going. The more feed back i have on this project the better!

KenM and jbarsile have stated (KenM seemed under duress at the time of his remarks ;)) that sticking with R-12 is the way to go for our older cars when possible, yet both tout the good cooling qualities of R-134a in a properly built and cleaned system. How long R-12 will be available in the States, who knows?

I need to replace the compressor  (frozen) and dryer too, so the system will be completely clean except for the hoses which have their own debated threads.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 02 February 2012, 12:06 PM
Had it been converted to r134a?  You can tell by the service valves.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 02 February 2012, 05:21 PM
No, all original, 3 owner car - 2nd owner did nothing and owned it for maybe a year before i got it.

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/ACvales.jpg)

I was a sucker for all that chromed trim, more interior room than my 85 300D and overall look with light gray body over black leather interior!


Chris

Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 03 February 2012, 07:41 AM
I say stay with r12 if at all possible. The consensus seems to be that our AC systems work better with it.

Refrigerant threads are like oil threads and it all seems to come back to the bumpers  ;D

I was using r134a in my original system and it was cooling pretty well.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 03 February 2012, 04:06 PM
Still making slow progress but finally i have evaporator/heat exchanger out!

Hey, Major Tom, if you're reading this thread please chime in on the type of foam you used to repair/rebuild your "airbox." So far your thread http://forum.w116.org/interiors-and-exteriors/airbox/ (http://forum.w116.org/interiors-and-exteriors/airbox/) is the only detailed info i have found. Any help would be welcomed.

Joe, If you are around...what rubber bits are available for replacement for this overhaul? The rubber grommets between cabin and wiper area (?) are hard and cracked. Also between firewall and wiper area - especially the right side above exhaust manifold.



(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/evap.jpg)


There's that missing floor vent pod - i knew it was somewhere.
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/bottomventsection.jpg)


Evap/heat box and lower vent section
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/evapandlowervent.jpg)


What should i used to clean up the oil tape residue off the expansion valve? Anyone?
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/expansionvalve.jpg)

Disassembling evaporator hopefully starts tonight!

chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 03 February 2012, 09:40 PM
I am in way over my head but things seem doable with forum help and service manuals.

Currently stuck removing evaporator core from box as the ETR switch wire is preventing further removal at this point. Time to locate a good a/c shop here in Seattle. Anyone know of any decent shops to test evaluate evap and heater cores? What is the proper procedure from here? I did not start out planing to go THIS FAR at all! Original problem was a shutdown issue linked to torn defrost poddiaphragm....LOL


Is the evaporator core OK? ???  There is a fair amount of rust at sides.

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Evapcoils.jpg)



ETR wire - i have disconnected ETR switch and gently pulled but don't wish to damage core. How to remove???
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/ETRswitchsensorwire.jpg)

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/ETRswitchsensorwireextraction.jpg)


Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 06 February 2012, 04:26 AM
Brave man Chris, your scope of works has certainly ballooned out on you there, no going back now. I continue to be amazed that you can still get R12 in the US, it must be starting to dry up though.

The issue with the barrier hoses is that 134a does indeed have a smaller molecular structure than 12, not as small as some other newer refrigerants and if your hoses are in good condition it is likely not

to be a problem, but if your hoses are 10, 15, 20 years old or more they are most likely porous to some extent anyway so replacement would not be a bad idea whichever refrigerant you choose. The

other thing to keep in mind is that O rings, the compressor shaft seal and other components may not be suitable for the synthetic oils that R134a requires. If you are replaceing the compressor make sure you

get one with seals suitable for 134a, you can still run R12 in it. That black goop around the tx valve is tar impregnated cork tape, clean it up with kero, very messy. You can buy a roll of new tape from a

supplier. I'm not familiar with the ETR switch you have there, but you will probably find that the end is just pushed into the coil, or there may be a small pocket that it slides into attached to a tube in the

evap.  Not much to be done about the rust on the evap end sheets, it shouldn't cause any problems by way of generating a leak, maybe hit it with some rust converter and paint over.

Good luck, you're going pretty well so far, keep us posted.

Cheers,     
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 06 February 2012, 04:29 AM
Hi Chris,

Sorry I haven't been around much, just very busy right now!!!

Wow!!! You are doing what is probably the most complicated, time consuming and expensive jobs on a a 116 or any car for that matter!

1) R-12 vs R134 - if your system is leak free and you can get 12 in your area go for it, otherwise bite the bullet replace the drier, expansion valve and go 134. You are going to need a new compressor anyway so no need to overhaul the old one. As far as hoses, I did not replace mine and have had no leak issues for the past 18 months. Mi expansion valve was not changed either and I do notice  a slight drop in efficiency on super hot days but only up until the system is on for a little while, then all is normal

2) Your evap looks fine from the pictures, they are made out of copper and will last forever! To clean the evap, heater core and heater box you should use soap and water with the help of a brush, to work the tight spots, fins, etc...

3) ETR switch - as far as I know the capillary tube is simply inserted into the evap core through a tube, spray some wd 40 and see if it starts to pull out

4) Grommets:

107 997 01 81 - heater pipes through firewall - $12.60 ea x 2 (14.00 list)
116 997 04 81 - a/c hose through firewall - NLA
116 997 10 81 - wiper cable to cabin - 2.53 (2.70 list)
116 997 22 81 - a/c hose RH - 0.90 (1.00 list)
116 997 00 81 - cowl drain hose grommets + a/c hose grommets - 1.35 x 4 (1.50 list)
116 997 16 81 - vacuum hose grommet - NLA
116 997 02 81 - grommet firewall - 3.78 (4.20 list)

I may have left one or more out, pls let  me know and if you could check the actual p/n's on the grommets installed in the car we can determine if this list is correct and what is missing.

Tks,

Joe


Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 06 February 2012, 07:30 AM
Chris, I forgot to mention: BE VERY CAREFUL not to let any water into the evaporator so make sure you close up the tubes pretty tight.

Tks,

Joe
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 06 February 2012, 09:00 AM
I used some vacuum plugs from an assortment picked up at a parts store to keep my evaporator sealed.  If possible you could purge it with inert gas like argon and then cap it.

You'll also have to change the O-rings on the compressor manifold and they are different from r12 to r134a. The service valves will need to be addressed as well.

You may want to call around to some AC shops and see if anyone has the equipment to deal with r12. You may get lucky and find someone or you could find some r12 for sale and leak check/charge yourself.

You say your car wouldn't shut off  ;D
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 07 February 2012, 01:23 PM
Update - ETR switch just needed to be pulled a little harder. Heater and evaporator cleaned up and waiting on the rust converter to dry and washed the main airbox housing. Moving forward with re-foaming lower vent flaps. Disassembled flaps and that sneaky vacuum pod. Off to the foam store to match existing before cleaning up


This is after removing the loose rust and applying rust fix 

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/CIMG1114.jpg)


Left vent coming out

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Leftfloorsideventflap.jpg)


Think i will use my heat gun to soften up the plastic to replace vents - really needed to bend the side support more than i like, but Major Tom made it without breakage. So far me too.

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Removingrightfloorsideventflapforrefoaming.jpg)


Vacuum pod is getting new diaphragm (from George Murphy) and rubber supply hose

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Lowerairboxtraycompletelydisassembled.jpg)



Next up is the defrost vent foam - not sure how to remove flaps from control rod. These flaps do have 2 sets of 3 pinch connectors (old fashioned clothes pin) so that might be all that is needed to remove.

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Defrostventflaps1.jpg)

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Defrostventflaps2.jpg)

Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 07 February 2012, 04:42 PM
Wow! Great work!  Friggin' leg flap pod is buried deep  :o

Any ideas about what type of foam to use?  It looks as if they just used contact adhesive to hold the foam in.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 07 February 2012, 04:50 PM
Chris, we are going to have to name you Mr. AutoTemp II !!!!! Very nice Sir!!!

I believe the foam used is pretty thin and pliable, it's function is to cushion the flaps when they close and seal the openings.

Tks,

Joe
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 07 February 2012, 07:23 PM
You guys are TOO kind!

Without the forum for support and knowledge I would still be pressing my [DEF] button to shutoff my car ;D Of course that was when my car actually ran.

Just picked up some foam today (3mm or .125") but not sure if the cell structure is dense enough. Seems about half as dense - new foam has more open space than original but thickness is about right. This begs the question ...what is the purpose of the foam in the first place, sound deadening or sealing off airflow?

(edit - Sorry Joe, missed part of your post - eidt) Should i look for a denser foam or not a big deal?

Right vent flap foam comparison
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/mainflaparea2.jpg)

Different angle
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/mainflaparea.jpg)

Bottom side of lower airbox tray connection to rear floor duct section - this 1/2" foam is just right, maybe a little denser but will work. Too bad they did not have any in 1/8"
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Halfinchfoamforrearfloorventducts.jpg)

Defrost vent foam comparison
(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Defrostventfoam.jpg)

Thanks,
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 08 February 2012, 02:07 AM
Check with some a/c wholesalers Chris, you can buy rolls of foam tape with a sticky back in many widths and thicknesses, might be something you could use and stick straight on. I would be careful using a

heat gun on your plastic, if you stress it while it's hot it may not go back to the original shape. Just a thought.

Cheers,
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 08 February 2012, 05:37 AM
Chris,

The 1/2 inch gray foam looks perfect. The white one seems a little too open, try to find one with a little more density to it so you get a better seal when the flaps close. Ken made a great suggestion regarding the foam with adhesive back, should be easier to work with as long as the glue is strong enough to keep the material in place, remember that the foam can become humid due to condensation form the a/c system so it needs to be able to stay put indefinitely.

Tks,

Joe
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: Hemersam on 14 February 2012, 02:05 PM
Since so many of you are responding to this work, let me toss in an anemic observation. The a/c/heat in my '78 280SE works fine (as fine as possible), but the drain from the heater/ac box stops up after using the a/c for very long; when I make a hard right turn, water pours down onto my accelerator foot. I'm told it's because the "pan" on the bottom of the a/c/heater box is stopped up. When the drain tubes are blown out by compressed air, things work for a short while, then here comes the water again.
I'm told it's necessary to get into the box itself and clean it out, which requires removing the center console and bottom part of the dash to get to it. I'm too old for this kind of project and have to pay to have it done. Is this the correct way to solve this problem, and if so, how many hours would it take a tech to do it? Any guidance here? Thank you.
Hemersam
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 14 February 2012, 03:13 PM
Hemersam - Others will chime in but i would think 4 - 6 hours for someone who has done it before or similar jobs.

Sounds like dirt/debris and maybe old foam clogging up your drains - 2 i believe on the 78. I have 4 drains on the 80.

Another thought is that mud or dirt/oil mix is clogging the drain tubes from the outside.  Maybe the tubes themselves are failing, not allowing condensation to pass.

Things that need removal:
Pull the seats
Pull center console bits
Pull the lower dash and kick panel bits left and right
Pull the tunnel
Remove rear floor heat ducts left and right
Remove 4 clips (2 front, 2 rear) and slide out the lower tray/vent section

Chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 14 February 2012, 04:03 PM
I gained access to the drain hoses by removing the lower dash panels and gently moving the console "wings" Mine were plugged with rust colored pieces of foam.

The way Chris described would be best but man, what a lot of work!
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 17 February 2012, 07:33 PM
Time to reverse the process....


Need to get that stuff off the dinning room table before my wife gets home  :o

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Assemblytime.jpg)   

Airbox consists of mainbody where evaporator sits, a framed section separating evap from heater cores, front section houses defrost vent flaps and the lower tray piece. I have installed new foam on the floor vent flaps, defrost flaps and connecting point between rear floor ducts and airbox lower tray. All airbox sections washed, heater and evap cores cleaned, rust inhibitor applied and painted with copper colored rattle can on hand. Still need to add new 1/4" open-cell foam around perimeter of both evap and heater cores to direct airflow through finned sections.

I have in hand a new replacement expansion valve (not installed yet) original  p/n 115 835 00 72.
(?)  Any sealing compound used on expansion valve flared (compression) fitting threads???


(?)  Regarding neoprene seal...this creates a water tight seal for condensation, should i replace with new? FSM states "replace cord," so i guess so. Total of 3 neoprene sections: pictured is longest and travels around bottom of the main body of airbox between center heater frame section and main body, separating evap from heater core , probably 18 - 24". The other two 5" sections are slightly higher up and separate front section from middle heater core frame - probably for noise reduction rather than water tight seal.

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Neoprenetubeseal.jpg)


(?)  A/C hoses - buy new? Seems only one a/c shop in the area works with r-12.

Stopping by another (closer and in business since the late 80's) a/c shop i could not acquire the 1/4" dia. neoprene cord but they did give me 2' of cork tape for free ;D. They also suggested, as a friend had, to go to Northwest Air Conditioning in Seattle who can use my hose ends with new hose sections.
http://seattle.citysearch.com/profile/10806622/seatac_wa/northwest_air_conditioning.html (http://seattle.citysearch.com/profile/10806622/seatac_wa/northwest_air_conditioning.html)

Thanks,

Chris



Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 17 February 2012, 10:04 PM
Here is a look at the exploded view of airbox sections


Blue tape on heater core is where i will attach semi-dense open-cell foam around perimeter with contact adhesive to replicate original condition.
Evap core receives similar foam treatment but just held in place (friction fit) between coils and upper/lower sections (heater core has metal frame to attach foam with adhesive).
Lower airbox tray section (right side in picture) vac pod rebuilt with new diaphragm (thanks george murphy), still needs black rubber hose section attaching pod to internal pass through nipple.
Bottom section of white vac pod (left hand side of picture) for defrost will be fully replaced with new purchased dual chamber pod and pink (center vent) pod gets new diaphragm.
Still need to replace old expansion valve

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Explodedview3.jpg)


Need to replace gromets at the heater hose to heater pipes located at cowl (lower 2 below) 107 997 01 81 - heater pipes through firewall - $12.60 ea x 2 (14.00 list).
Upper gromet (below) is in engine compartment above servo, at firewall. Joe has it listed NLA...maybe a standard graomet without the neck will work there?
116 997 04 81 - a/c hose through firewall - NLA

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Firewallgromets.jpg)
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: koan on 18 February 2012, 12:32 AM
Another good thread with pictures.

I really appreciate posters who (remember to) take pictures of their work, they're a valuable record for the next guy.

koan.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: Hemersam on 18 February 2012, 07:06 AM
'78 280SE.  Yesterday, I noticed that both windshield wiper camshafts have no rubber grommet; they've apparently rotted away. I suppose water could leak through those smal un-sealedl openings, but would it drain into the area below the hood vents (thus into the vents to the engine compartment), or would it leak into the passenger compartment? Thanks.
Hemersam
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 18 February 2012, 09:03 AM
Koan - Thanks. I have a lot of pictures and skipped some segments - making templates for the lower vent flaps and defrost flaps as an example. Moderation in all things is a good goal. Happy to supply more pictures to those that want/need them. Think my biggest job before this was front wheel brake job with new rotors and inner and outer bearings - even bought the dial gauge to measure wheel play rather than the Haynes' procedure of tightening the locknut while rotating the hub until tight and then backing off a 1/3 of a turn - some people swear by it, others curse the procedure.

Hermersam - Not sure what you are describing. Looked in my FSM and online with EPC and can't locate a exploded view of wiper assembly - i just love those exploded views...a picture can list a thousand parts and the order they go in. Truly a thing of beauty.

I took this picture of my left hand side of the cowl area. Anything here what you are referring to?

I need to replace the fiber, or very hard rubber, washers that go under the metal washer at bottom of wiper spindle(?) . An exploded view would be nice.....as i don't recall the order but someone will chime in.

(http://i1216.photobucket.com/albums/dd362/ckamila99/300SD/Wiper-cowlarealeftside2-1.jpg)
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: Hemersam on 18 February 2012, 11:18 AM
CKamila: the windshield wiper spindles which protrude slightly out of the hood vents and onto which the wiper arms are attached. There is no rubber around the spindles.
Hemersam
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: koan on 18 February 2012, 01:05 PM
I have a lot of pictures and skipped some segments - making templates for the lower vent flaps and defrost flaps as an example. Moderation in all things is a good goal

I put my pictures in a "koan" album in the gallery, and into sub-albums on subject, that way they stay around as long as the forum does. Also I rarely post big pictures in a thread, just a single clickable thumb nail to the sub album so only those interested have to see 67 pictures of the screws that hold the astray in ;)

koan
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 18 February 2012, 11:08 PM
koan - I like your method and will work to move to that format. Given the added pictures...who picks up the bill for hosting and storage costs?


chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: koan on 19 February 2012, 10:37 AM
who picks up the bill for hosting and storage costs?

Have you not paid yet?

No, our much esteemed admin carries the costs.

koan

   
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 19 February 2012, 01:49 PM
Ready to switch out the expansion valve with new. I don't see and info regarding sealing compound for threads - probably would introduce junk into system.

Removing old valve i did notice copper sealing washer. Will this washer need replacing or can i reuse? No copper washer listed on EPC just a filter p/n A 108 835 02 47. Must be for hose as i don't see any removable filter within expansion valve high pressure connection.

(http://gallery.w116.org/dl/36168-1/ACC.jpg) (http://gallery.w116.org/dl/36206-3/copper+sealing+washer.jpg)


Anyone know where to get the 5mm sealing cord - see link step #15 http://handbook.w116.org/Climate%5C83-538.pdf (http://handbook.w116.org/Climate%5C83-538.pdf)
I am guessing sealing cord is neoprene but can't locate a source locally or web. Will try dealer tomorrow.

(edit - found supply of sealing cord and P/N is 000 987 51 33)

(http://gallery.w116.org/dl/36171-4/Sealing+cord.jpg)


thanks
chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: koan on 19 February 2012, 07:49 PM
Will this washer need replacing or can i reuse?

It should be replaced, old washers harden with age and won't deform to seal again.

Replacement washer will be flat, any auto place should have them

If you cant get a new washer clean up the old one, and re-anneal in a gas flame and let it cool in the air.

koan
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 19 February 2012, 10:27 PM
Will this washer need replacing or can i reuse?



Replacement washer will be flat, any auto place should have them


Have to correct you there koan, that's a flare washer and they come that way, you can make your own Chris if you have some tubing, flare block and pipe cutters, otherwise just do as Koan says and heat

him up with an oxy for 2 secs. You can buy new ones at a supplier if it goes to poo. Probably best to have one in there, especially if you are going with 134a. You can use a sealant, a specific one made for

refrig and a/c but just a TINY bit, a smear is all you need. That sealing cord looks exactly like what's in the evap box on a landcruiser, should be able to get a roll pretty easily somewhere.

Cheers,
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: koan on 19 February 2012, 11:01 PM
Have to correct you there koan, that's a flare washer and they come that way

Never realised that  they came that way

koan
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 20 February 2012, 12:01 PM
Ordered new flare washer but a big NO on the sealing cord. Parts guy at Phil Smart (Seattle area dealer) suggested butyl cord.

KenM - any further info on the thread sealing compound?

Joe - i would like to order a few parts when you have the time. Suggestion on substitution for NLA parts (116 997 04 81 - a/c hose through firewall - NLA)

Off for a short holiday.

Thanks to all

chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 20 February 2012, 02:48 PM
Hey Chris, you can just use refrig oil if you have some handy, put a drop on the front and back of all your flare faces, or you can buy a sealant, I use stuff called leak-lock, comes in a small blue tube, just smear

a bit on the flare faces. Just don't put it together dry, that's when you will have troubles later.

Cheers,
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 20 February 2012, 05:13 PM
Hi Chris,

Pls email me the list to  joe@mbklassik.net and I can confirm prices and availability.

As for the NLA hose, take the old one to a good a/c hose shop and they should be able to make one for you using the original terminals.

Tks,

Joe

Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 25 February 2012, 08:56 PM
Question, are there 2 different expansion valves available: R-12 and R-134a?

This link shows 2 different valves with the original part # across the top, while the second valve has R-134a on top. I purchased the original style R-12 I assume given the part #.

http://catalog.peachparts.com/ShopByVehicle.epc?q=1980-Mercedes--Benz-300sd-Climate--Control&yearid=1980%40%401980&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6204%3AED|10000133%3AMBC|1509%40%40300SD&catid=242213%40%40Climate+Control&subcatid=242233@@A%2FC+Expansion+Valve&mode=PD (http://catalog.peachparts.com/ShopByVehicle.epc?q=1980-Mercedes--Benz-300sd-Climate--Control&yearid=1980%40%401980&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6204%3AED%7C10000133%3AMBC%7C1509%40%40300SD&catid=242213%40%40Climate+Control&subcatid=242233@@A%2FC+Expansion+Valve&mode=PD)


R-134a                                                                   R-12

(http://gallery.w116.org/dl/36565-3/134a+expansion+valve.JPG)                  (http://gallery.w116.org/dl/36562-3/115+835+00+72.JPG)


Also picked up a new Receiver/Drier and Behr compressor where it clearly states "R-134a only." I thought type of refrigerant used depended on type of seals and oil. Is there a specific R-12 or R-134a compressor? Please excuse my ignorance on all things a/c.... ???   Maybe it's time to pass off the ac stuff to the pros as i am swimming in murky waters with  R-12 this and R-134a that.

Behr info:
620230
QTY 1
20110218
8FK 351 316-221


thanks

chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 26 February 2012, 05:22 AM
Which refrigerant are you going to use Chris? You won't be able to use a R12 compressor with 134a, the drier won't matter and you will probably get away with a 134a tx valve on R12 but the compressor

won't do. I thought the compressors were the Fridgidaire A6 type, haven't seen a Behr one before.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 26 February 2012, 10:30 AM
KenM - OK, coolant refrigerant and compressor MUST match. Got it (finally). 

What refrigerant will i use....R134, i think.  ??? The R12 seems to be a big hassle and waste of time/money as the only shop working with R12 is 30 miles away, which only offers clients first come first serve type of service. They are the best shop in t he Seattle area and i might need to go there anyway as they also "have all the equipment to create new hoses from my ends" - at least that is what another a/c shop stated which has done a/c work for 20 years but no longer does R12.

you will probably get away with a 134a tx valve.....

I thought the compressors were the Fridgidaire A6 type, haven't seen a Behr one before.

Ken I assume from your statement and the posted link there is a specific a R134 valve to match the R134 system. Is the valve less important in the overall picture? Seem to recall Joe using his original R12 tx valve in a R134 converted system. I have the chance to match everything and easily replace questionable parts/hoses. I have a new tx valve with original part # so i believe that must be a R12 so i would want to exchange it for proper match, yes?

This Behr looks to match the original in size and shape, while the A6 is much longer. This new compressor is for the 300SD. I believe the other non diesel 116's use the A6.

              R4 compressor                                          A6 compressor

(http://gallery.w116.org/dl/36570-3/R4.jpg)             (http://gallery.w116.org/dl/36568-3/A6.jpg)

thanks

chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 26 February 2012, 10:52 AM
Question - In a properly a/c system without leaks, be it R12 or R134, how long before the system would need some form of maintenance like additional refrigerant? This might help with the overall debate or refrigerant type.


thanks,

chris
 
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 26 February 2012, 11:53 PM
I forgot that the diesels have a different compressor from either the 6 or 8 petrol engines. If you're going with 134a I think that's the best idea Chris, certainly if you have the opportunity now you should get a

134a tx valve while you have gone to all this trouble. Hoses as you say can be remade, make sure they use barrier hose. Once the system is running, I would imagine a drier change would be in order after

100 hours or so running time and then provided the system is tight you should not have to top up the charge for many years. A good and thorough installation is the key to reliable and trouble free system

operation, or certainly a very major factor.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 27 February 2012, 03:12 PM
Hi Chris,

If you are converting to 134 then make sure everything matches including the tx valve, the valve will be marked 134A. Your compressor is actually a Delco R-4 which is now made by Air Products. The rec drier is not gas specific as Ken said but if you ever consider going back to R-12 then it must be replaced.

Since you have the whole thing apart this is the time to get the correct Tx valve, it will make a difference in the system's performance. I did not replace mine or the hoses and have had no leaks in almost 2 years.

A tight system that is properly charged and used regularly will last a very long time.

Tks,

Joe
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 27 February 2012, 08:09 PM
Hey Joe - there seems a constant stream of questions on this subject for me of course and truly i need to start moving forward on this project. Joe, beautiful job on that 1970 300SEL restoration!


What about the high and low side valves? Wouldn't they need to be the newer 134a type as well. Would the a/c shop replace them or is that another purchase? I assume the valves are removable.

As for the compressor i'll take your word for it - you da man, but that picture was taken from a web site to show Ken the difference  trying to share what little knowledge i have ;D or not  :-X . Mine is shown below.

(http://gallery.w116.org/dl/36797-3/Compressor.jpg)
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 27 February 2012, 11:07 PM
You will need different access valve fittings with 134a Chris, you can get adaptors to fit on an existing R12 fitting or you can get them as part of a new elbow or straight section that attaches to hose. You also

need different adaptors for your gauges to connect to the system, the 134a type clip on like an air line fitting.

Some info here could be useful.

http://www.highgateair.com.au/images/stories/products-pdf/Compressor-Spares.pdf
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 28 February 2012, 05:39 AM
Hi Chris,

Cool you got a Behr compressor! I did not know there was a version of the R-4 made by them, the design is originally from GM / Delco.

As Ken said, once you convert the shop will install adapters to your hi and low pressure fittings so they can hook up the 134 machine to it. Since you are having new hoses made, I would probably replace the valves at the same time, makes for a much cleaner look and you are assured to have all new parts an no chance for leaks from the old valves.

The 300SEL is going slow right now.... I need to finish a Corniche Coupe that is giving me the fits.... once I am done it will be 6.3 all the way to the end, plan is to deliver the car around July.

Tks,

Joe
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 28 February 2012, 07:03 AM
Thanks Ken and Joe.

Since i will assemble and install airbox prior to dropping off at a/c shop, should i flush the evaporator with some chemical now to remove oil/contaminants  while evaporator is out and tx valve is off or have shop do it with tx valve on? How large is the diameter of 134a tx valve orifice? If i flush any recommendations on brand or type of chemical or those to avoid. I just want things done the right way regardless of who does the work.

Anything else you guys or anyone have for additional input of items not covered?



thanks,

chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 28 February 2012, 07:56 AM
Chris,

I really don't know what the shop uses to flush the evap, maybe you can ask them and see if you can do it yourself. Otherwise just let them do it and you should be fine.

Looks like you've covered everything, one last thing to look into is the operation of  the aux fan. I would recommend  you have it connected so it comes on together with the compressor, this will make sure your engine always stays cool and it will help increase condenser efficiency by lowering its temp and help compensate the slightly lower performance of 134 in these older systems.

Tks,


Joe

Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 28 February 2012, 08:19 AM
ETR switch connections - After having another look at the wiring diagram I see many of the other switches don't have terminal #'s listed so i guess the answer is no it won't matter which wire connects to which terminal as this just creates a connection between point "A" to point "B"

_________________________________________________ _________________________________________________ _________________________________________________ ____________
Original question - While removing airbox i missed disconnecting/observing ETR wire locations.  I have a original ETR switch and new replacement. FSM schematic shows one wire connecting from ETR to #18 (double contact relay) while the other wire connects to #25 (pressure switch) but don't' see which wire goes to which terminal. New switch has terminals #4 and #3 opposite end of probe wire while original has 2 terminals on top but don't see and markings.

Since this is a switch in either open or closed position will it matter which wire goes where?
_________________________________________________ _________________________________________________ _________________________________________________ _______________



http://handbook.w116.org/Climate%5C83-605.pdf (http://handbook.w116.org/Climate%5C83-605.pdf)

thanks,

chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 29 February 2012, 03:43 AM
Flushing the system is best left until last Chris, or at least until the system is complete and won't be modified again, BUT, you must remove the tx valve and replace it with a section of hose or pipe. Do not

attempt to flush the system with the tx in place, you will just fill it up with crud and it will be ruined. Same goes for the compressor and drier, bypass them and pump the solvent around the system, then

evacuate the system to remove all solvent before refitting components. Probabaly best to leave it to a shop as long as they know what they are doing. I must admit I have never seen the point of wiring the

auxillary fan on all the time, 100 degrees is 100 degrees regardless of the refrigerant in use, the pressure differences between 12 and 134a are pretty small really so the effect should not be that great. Joe

has probably much more experience than me of driving a 116 in traffic though, so l stand to be corrected there.

Cheers, 
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 01 March 2012, 05:18 PM
I flushed my evaporator with some commercial cleaner. It had a citrus smell and removed a good bit of crud from the tubes!

There are also some oil issues. The R4 was designed for ester oil or mineral (I believe) and R12. If you switch to R134a you'll need PAG oil and the volume is important because of the radial design of the R4. It has no sump so it relies on circulating oil for lubrication more than other types.

If at all possible I'd stick with R12.  That way you can use the oil the compressor was designed for.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 07 May 2012, 02:48 PM
Update: Well it's been a long time since posting...i got a little side tracked and did a few other things and found it's FAR easier to disassemble than re-assemble. Airbox now re-installed and just sorting out center dash wiring and vacuum lines. some lines still have a little oil from t he past which i will flush with solvent and compressed air. My #26 wiring connector is not clipping into the male section - not sure what's up - so i might just use wire ties to secure in place. Since this is just a switch and the connector appears to go either way i assume it can. #27 connector is facing with keyed (cut a-way) section towards valve, while #25 is the other way round as that's how i connected them.


Jon - i did/will end up with R12



(http://gallery.w116.org/dl/38586-3/Getting+close.jpg)  [size(http://gallery.w116.org/dl/38589-3/switchover+valves.jpg)




Found a trick on the center vent side clips. Joe originally stated only needed the back clips and the rubber boot section would hold it in place. Well trying to connect the back clips is tough by itself since you can just barely squeeze your hand through the cut out section and then blindly press clip in. My though is i would loose the back clips too...so i tied a section of dental loss to both side and back clips to retrieve when they dropped. Once in i just snipped the excess.
(http://gallery.w116.org/dl/38585-3/center+vent+clips+install.jpg)  (http://gallery.w116.org/dl/38592-3/center+vent+clips+install+2.jpg)


Other items:
repainted air cleaner, metal water lines, brake booster, master cylinder and head light covers
wash out all sections of heating/cooling system duct work and vents
dealt with a little bit of rust
disassembled wiper fluid pump, cleaned, painted rusted bracket, installed
new battery tray - old one rusted through causing other surface rust issues in front right section (LHD)
replaced all the rubber 3 and 4 way connectors and rubber connecting sections
new servo and blower brushes from george murphy
rebuild blower housing and installed new foam on flaps
cleaned carpets
installed new grommets and other bits i received from Joe - Thanks again!


To do:
finish current project items - install blower, servo, a/c compressor along with drier
install new vacuum pump
install new motor mount pads and probably at least one engine shock and top shock mount




hey, joe - that new replacement grommet for the NLA part fits great! Just trimmed the opening a little.


(http://gallery.w116.org/dl/38595-3/heater+hose+grommet.jpg)




thanks for all the help!


chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 08 May 2012, 09:35 AM
It's coming along nicely!
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 09 May 2012, 08:01 AM
Anyone know about a strainer located in the high pressure side of the expansion valve? I came across it in my hvac fsm but did not see it within the old valve ???


p/n 108 835 02 47


item 10 in epc drawing






(http://gallery.w116.org/dl/38606-3/EPC+108+835+02+47.jpg)       




(http://gallery.w116.org/dl/38600-3/AC+FSM+83_3-534-1.png)

http://handbook.w116.org/Climate/83-534.pdf (http://handbook.w116.org/Climate/83-534.pdf)


thanks,


chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 09 May 2012, 06:27 PM
I was expecting to find one in mine as well but it wasn't there  :o
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 10 May 2012, 05:00 AM
Depends on the make of valve, some have them and some don't, better to have one to prevent tiny pieces of crud from blocking the valve orifice, on the other hand with the valve in such a bugger of a position

to get at I imagine it would be looked at very seldom indeed.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: jbrasile on 17 May 2012, 08:57 PM
Hi Chris,

Nice!!!  You are almost there...

Glad to hear the 113 grommet worked!

Great idea using dental floss to keep the darn clips from getting lost.

Tks

Joe
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 23 June 2012, 10:28 PM
Near the end now.....all put back together except passenger seat and lower dash panels. Still need to replace a/c compressor and dryer


I double checked the old expansion valve and sure enough there was a mesh filter deep inside but blackened so hidden in the shadow. What kind of gunk is this and why is it black? Have replacement filter for new valve ready to go. The new and old mesh appears to be copper just hard to tell from photo.


(http://gallery.w116.org/dl/39004-3/high+side+copper+mesh+filter+for+expansion+valve.jpg)




thanks,


chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 24 June 2012, 08:11 AM
It loos similar to the stuff I found in my drier:

(http://i711.photobucket.com/albums/ww112/jhoff/IMG_2266.jpg)

Maybe just old funky oil?

Did you replace the stuff in the bag:

(http://i711.photobucket.com/albums/ww112/jhoff/IMG_2269.jpg)

 ;D
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 24 June 2012, 08:53 AM
Jon - are those Trade Joe's Fruity-O's? What's there absorbent qualities compared with just plain O's? I believe the green one's are R-12 compatible too.


I don't recall, did you use something to flush out your hoses? Guess i need to open my drier too if for nothing else "because it's there."




thanks,


chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 24 June 2012, 09:56 AM
Good eye! those are indeed Trade Joes. There is a formula for calculating the green/orange ratio based upon ambient temps in K and the proportion of PAG binomial isomers to low side partial pressures of long chain hydrocarbons:

(http://i711.photobucket.com/albums/ww112/jhoff/e9.gif)

 You must also calculate the dynometric flows between evaporator CFM/condensing volume at sea level but that goes without saying. Just be careful about the inverse ratiometric values because we all know what happens when the divergent values approach the limits outlined in Boyles 3rd law.

 ;D

I actually changed all my hoses to the new barrier type but I would look into flushing yours.  It may not be a bad idea to run yours for a while and then evacuate the system and change the drier. The filter in it should pick up any crud left circulating in the system. It may be overkill but you have sooo much work in it.

Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 26 June 2012, 04:51 AM
That's a beautiful looking gauze filter you have there Chris, the black stuff is the lining from inside the hoses, breaks down over time with the addition of heat. I would say it's an absolute necessity to replace

your filter/drier if you haven't already done so. It will probably look something like Jon's inside. Looks like you're on the home stretch now.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 26 June 2012, 08:05 AM
KenM - I think molasses in winter moves faster than my projects........still need to pull the original compressor and drier and replace both. Will blow out the hoses when the all the bits are disconnected, reassemble and drop off at the a/c shop for leak testing prior to filling.


Question: is it better to pressurize the system or pull a vacuum for leak testing? I am sure the shop knows but i like to have as much knowledge as possible - one reason my projects take soooo long.


thanks,


chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 27 June 2012, 04:22 AM
You need to pressurise the system for leak testing Chris, ideally it should be tight before you pull a vacuum otherwise you will be sucking air and contaminants into the system. It's helpful to monitor the level

of vacuum to see that it doesn't rise but the system is designed to hold pressure not vacuum. The compressor shaft seal can often leak a bit under vacuum for example but be perfectly good under pressure

because that's it's design function. This is the reason you must never rotate the compressor when the system is under vac beacause little specs of grit etc will get sucked into the seal and potentially ruin it in

a short time. Would pay to give the hoses a good flush with solvent by the looks of your strainer there. Keep up the good work!
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 27 June 2012, 04:25 AM
Good eye! those are indeed Trade Joes. There is a formula for calculating the green/orange ratio based upon ambient temps in K and the proportion of PAG binomial isomers to low side partial pressures of long chain hydrocarbons:

(http://i711.photobucket.com/albums/ww112/jhoff/e9.gif)

 You must also calculate the dynometric flows between evaporator CFM/condensing volume at sea level but that goes without saying. Just be careful about the inverse ratiometric values because we all know what happens when the divergent values approach the limits outlined in Boyles 3rd law.

 ;D

Dammit Jon, are you taking the piss with all this? I'm just not sure after being bamboozled by your recent electronics posts.  8)
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 28 June 2012, 10:05 AM
A year of daily driving a vintage MB diesel about 1000 miles a week does weird things to your mental health  ;D I don't think I'm completely insane... yet  :o I believe the recent electronic fumbling hasn't helped matters much though...

GREAT explanation on the leak testing Ken!  Things seem to make sense once you dive in.

Just a few ramblings to add...

Make sure you reinstall the little conical crush washer between the evaporator and TXV. Mine leaked like crazy before I figured out it wasn't there. I guess the copper flare won't seal against the brass TXV without it in place.

I've read that the best way to leak check here in the US, (EPA compliant, etc.) is to charge the system with nitrogen and a little bit of R12 (Although, it may be R22) and check it with an electronic sniffer. The R12/nitrogen is supposed to be a lot easier for the sniffers to detect than r134a.

You may want to look at this:

http://www.klimakit.com/klima-ac-compressor-upgrade-kit/

Which just became available. Sorry to add complications to an already complicated project  :o
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: ckamila on 28 June 2012, 01:47 PM
1980sdga - Well Jon i already have the R4 compressor so maybe when it fails i can give the Klima kit a go. Do you have a link to that testing procedure? Knowledge is power.


thanks,


chris
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: 1980sdga on 28 June 2012, 04:52 PM
I couldn't find a good link but it's outlined over on the peachparts diesel forum.

I looked at my AC notes and it looks like you pressurize with 200 psi of any "dry" gas and add 4 oz of R22 and then sniff. The R22 is supposed to be easier for the sniffers to pick up. R22 is a controlled substance though and it's getting pretty expensive  and getting more so every day.

Anecdotal and sort of OT but...

I was working on my home AC today (New start capacitor for the blower and low charge) and the guy at the AC shop said his R22 prices are going up 12%  ::) Like you said, knowledge is power!  Don't ask what I charged my system with  ;) but the wife is happy (And cool) again! All this learned from automotive forums!

Good luck! 
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: KenM on 30 June 2012, 01:03 AM
Those R4 compressors certainly have a bad reputation it seems, haven't worked with one myselfbut the Sandens are certainly a good unit.

I would be happy if R22 was only going up 12% Jon, we have a carbon tax that comes into effect here on July 1 and refrigerants are being hit hard, some types going up by over 300%. R134a is going up by

about 100%, list price will be in the order of $175/kilo, R22 will be a similar cost. Some of the commercial refrigeration gases are going to be around $380/kilo or more, that's gonna make your eyes water if   

your drinks cabinet springs a leak. It's going to cause some havoc, supermarkets have been scrambling for some time now to change to refrigerants like CO2 but it needs different equipment so not a cheap

option. I foresee beer going up too. There is a straight replacement for R22 now, R427a, haven't worked with it but it's supposed to be ok. I find it funny that you say R22 is a controlled substance now but

yet you guys can still get R 12. And yep the R22 or heaven forbid R12 are easier to detect, a good lectronic detector should pick up 134a pretty easily though.
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: phxadam on 25 April 2017, 11:36 AM
Which part numbers did you end up ordering for the AC host firewall grommets?
Title: Re: ACC overhaul - Heater box / evaporator removal
Post by: Squiggle Dog on 09 May 2018, 09:57 PM
Which part numbers did you end up ordering for the AC host firewall grommets?

Possibly 113 997 01 81? I need to replace my firewall grommets as well since I have my whole heater box out of the car.
(https://cdn3.volusion.com/r4zy7.bgtw9/v/vspfiles/photos/AUTH-004529-2.jpg?1523814406)