Author Topic: ACC overhaul - Heater box / evaporator removal  (Read 25390 times)

1980sdga

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #60 on: 08 May 2012, 09:35 AM »
It's coming along nicely!
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

ckamila

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #61 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://handbook.w116.org/Climate/83-534.pdf


thanks,


chris
If it's not broke i haven't fix it yet...


1980 300SD, 170K
1985 300D, 235K

1980sdga

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #62 on: 09 May 2012, 06:27 PM »
I was expecting to find one in mine as well but it wasn't there  :o
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

KenM

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #63 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.
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Chevy Chase: 'On the lips will be fine'

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jbrasile

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #64 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

ckamila

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #65 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.







thanks,


chris
If it's not broke i haven't fix it yet...


1980 300SD, 170K
1985 300D, 235K

1980sdga

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #66 on: 24 June 2012, 08:11 AM »
It loos similar to the stuff I found in my drier:



Maybe just old funky oil?

Did you replace the stuff in the bag:



 ;D
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

ckamila

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #67 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
If it's not broke i haven't fix it yet...


1980 300SD, 170K
1985 300D, 235K

1980sdga

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #68 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:



 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.

Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

KenM

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #69 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.
Mexican girl: 'We could go for a walk outside and you can kiss me on the verandah'
Chevy Chase: 'On the lips will be fine'

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ckamila

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #70 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
« Last Edit: 26 June 2012, 08:13 AM by ckamila »
If it's not broke i haven't fix it yet...


1980 300SD, 170K
1985 300D, 235K

KenM

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #71 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!
Mexican girl: 'We could go for a walk outside and you can kiss me on the verandah'
Chevy Chase: 'On the lips will be fine'

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KenM

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #72 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:



 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)
« Last Edit: 28 June 2012, 06:45 AM by KenM »
Mexican girl: 'We could go for a walk outside and you can kiss me on the verandah'
Chevy Chase: 'On the lips will be fine'

3 amigos

1980sdga

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #73 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
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

ckamila

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Re: ACC overhaul - Heater box / evaporator removal
« Reply #74 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
If it's not broke i haven't fix it yet...


1980 300SD, 170K
1985 300D, 235K