New member, new car, have brake, AC, and sunroof questions

[1980_300SD]

Hello all,

This is my first post here.  I have always had a 123 body style diesel, and just saved a 1980 116 300sd from the junkyard.  It was in pretty bad shape when I started and getting close to getting it roadworthy. 

Couple of things I really could use some help with:

1.  The brakes had some major problems when I got it.  Long story short, replaced pads, brake rubber lines to each wheel, MC, brake booster, and vacuum hose. 

The brakes now work fine, and can skid the tires, but if I press them hard, then again, then again (of course this usually never happens on the road), each time the brakes have less stopping power.  I am not sure if this is due to poorly bled lines, or if this is an issue with my vacuum system. 

Also, if I hold down the brake pedal, and turn off the car, it will take a long time to shut off.  But its a new booster.  So on these cars, if I hold down the brake is it normal to be constantly release vacuum?

So for this issue, I am not sure if I still have a vacuum issue, not sure if I am dealing with air in the system, or maybe the entire system is working as designed.  Any input on this would be helpful. 

2.  My sunroof closes almost all the way, but right at the end it makes a clicking sound, like it has run out of track.  If I push it back a little, I can get it to retract again.   With the other problems I am working with, I really only care that the sunroof is shut, so water stops leaking in.  Any ideas on getting this thing shut?

3.  Last issue, is the AC.  There is no charge whatsoever left in the system.  Since it is R12 and not been converted yet, what would be the best path to find out why its empty?  To try and find some R12, and see if there are any leaks?  Is there another process used to find leaks?  I could always convert to r134 but I would of course like to avoid that. 


Thanks for any help you can provide. 

[oscar]

Regarding the brakes, sounds like a vacuum leak especially how the engine runs on a bit after switching off.  I know you said the brake booster has been replaced but I'd try and attach a vac gauge to it, apply a vacuum  and test that it holds up.  Check the vac line for cracks too.  That line becomes brittle and if the booster has been changed the line has probably been moved round a bit.  If that's all ok check that the ends are attached firmly. Or rather do that first.  Eliminate the easy parts first. 

I'm not sure how efficient the vacuum pumps are on SD's but if you're idling and doing that brake test (on, off, on, off thing) you might be just using up the vacuum reserve quicker than the pump can deliver the suction.

Regarding the a/c, if you're planning on DIY, it might be best to add a fluro charge to the system and check for leaks with a UV light.  Replace what needs to be replaced and then recharge the system with your gas of choice.  Ideally you'd want to flush the system first and use a vacuum pump to evacuate the system and then recharge with your gas of choice.  All the bits you need are on ebay from tools, manifold gauge sets, r12/r134a adapters etc and if you're in the US you've got easy access to handy 12oz cans of oil, refrigerant and leak dye.  Here's a link to what I did a couple of years ago using a hydrocarbon refrigerant Link

Got no idea about the sunroof sorry.

[pez]

I can offer some help on the sunroof - perhaps.

I painted my car this summer and had to put the sunroof back in. It took quite some time, and patience to get it aligned.

Here is the process I followed:

1. Remove your sunroof headliner by prying the front edge out of the sunroof from the inside, roof partially open. Once the front clips are out, slide the roof all the way back while holding the liner. Remove the liner through the open roof upwards.

2. You have 4 places [each corner] where the roof is bolted on to the skids. Use this opportunity to lube your slides. Loosen all 4 bolts so that the plastic slides [I call them skids] can wiggle freely.  Also, remove your ramp pins [one on each side, has an 8mm head on it, pin sticks out the middle side edge of the roof to interact with the ramp that lifts the  tail end of the roof when closing].

3. Close the sunroof all the way. Take note of where it stops, and if it does go further with the skids loosened.

4. Open the trunk. On the drivers side inner trunk wall, to the left of your speaker, you will see a special tool for manually moving the cable. From my memory, you will drive it with a 17mm socket [same as your lug wrench] and the other end is a drag link that goes in to the motor. Pop it in the motor and verify that the cable is all the way extended [roof closed].  If you want to check the function of the cable/tube assembly, just manually crank it open then closed and what you feel is what he motor is dealing with.

5. So assuming that the cable is OK, and you have it fully extended [sunroof totally closed], go back inside the car and tighten the front bolts on the sunroof. Operate it a few more times [open and closed - and remember the motor will time out if it gets too hot - don't risk it, give it time!].

6. Check the exterior of the car to be sure the roof it totally closing. Now look at the roof's relation to the sunroof. Adjust your height on the rear of the sunroof using the plastic cam on the underside of the sun roof.  Adjust the front height using the flat head screw [one per side] that is in the middle of the chrome rail, towards the front.

7. Tighten down the rear bolts.

8. Check it all again. Don't rush to put the headliner back on - give it a few days of use to be totally sure.  Take this opportunity to use some high quality interior cleaner on your entire headliner. Also, get some compressed air and a nozzle and blow out all 4 sunroof drains.

Good luck!

[1980_300SD]

I really appreciate the help that has been provided so far. 

Thats a great detailed explanation on the sunroof issue!  Thanksgiving is this week so its family time and lots of work, but after the holiday I am going to get working on that sunroof, following the steps listed below. 

As for the AC Oscar, after reading your other post, you used propane to charge?  Is that what I understood from your post?

I have been told that "freeze 12" refridgerent is a good substitute to R12 in R12 systems  - and is mostly propane.  It is available legally everywhere and costs much less - and will mix with R12 - the downsides I have been told is that it does not quite cool as well as R12, and it makes your system a driving bomb in the event of an accident. 

Any opinions on this information?

[koan]

I have been told that "freeze 12" refrigerant is a good substitute to R12 in R12 systems  - and is mostly propane.  It is available legally everywhere and costs much less - and will mix with R12 - the downsides I have been told is that it does not quite cool as well as R12, and it makes your system a driving bomb in the event of an accident. 

I understand hydrocarbon refrigerants to be as good as R12 and certainly better than R134a in systems designed for R12. Only about 1/3 the charge (by weight) is required.

My usual response to the "accident bomb" question is 330 grams of hydrocarbon refrigerant that might leak into the cabin (and dissipate very quickly) is lot less of a concern to me than 90 litres of liquid hydrocarbons down the back that will spread around the car, but as you are diesel there is less risk of ignition.

There's plenty of info both for and against hydrocarbon refrigerants on the Internet, have a search.

koan

[oscar]

You beat me to it Koan   I'll add a bit.

My opinion towards flammable refrigerants is that they're all flammable, just some are more than others, and I'm very biased towards the use of hydrocarbon refrigerants.  So I'll admit it's hard for me to remain impartial.
Hell, even the greenies like the idea hydrocarbon refrigerants.

The stuff I used was a propane/isopropane mix.  It's a refined dehydrated formula designed for use in A/C systems.  It's not straight BBQ gas like propane. 

However, propane can also be used in car A/C's.  A problem it may have is that it actually works too well and as I understand, because it's not dehydrated and has impurities it can freeze in a system.  So many variables that can cause that

Freeze12 is what I first wanted to use but there was doubts over whether I could import the 12oz cans to Aus.  I can't remember what's in it now but then I heard about BBQ gas or propane being used in hotrods and kind of went from there.  I heard about this locally made stuff and bought it.  I'm not sure what's in the US whether HyChill exports to there or whether you just want to try BBQ gas. 

The downside of the HyChill stuff is that it's expensive compared to straight propane and whilst it's not illegal to buy the stuff in Aus, I came under a bit of scrutiny by dickheads that wouldn't sell me it saying that I needed to be licensed.  I ended up ringing the manufacturer to find a supplier.  It's a bit of a hot potato as the HVAC industry and trade union are threatened by the use hydrocarbon refrigerants and have campaigned to get it banned from being used and were successful in convincing one state government in Aus to ban it.  But I think that's been lifted.

There's a lot of scarmongering and then some decent info out there.  Good luck wading through it but apart from online, try and find more people (locally to you) that have used the alternatives.  There's so many variables relating to the state and condition of an A/C system that could cause bad or good experiences with how a certain product works.

[1980_300SD]

Koan,

Question on your response....

My concern about the car "bomb" in an accident would be with the blow up aspect if a front end collision were to occur, not what may happen in the cabin - of course both would be bad but im thinking crash+propane in the system up front from drier, and all other ac related parts = leak + spark or flame = bomb.

Maybe I am to paranoid - wouldn't be the first time someone said I was  

[1980_300SD]

Just saw your reply when I posted my last response Oscar. 

I have access to all the Freeze12 I need.  Its everywhere in Arizona.  I just have not had any experience with it so have not tried it. 

Sounds like it may be a good first step on this car, since I can buy it over the counter and not worry about a leak letting very very expensive and hard to come by R12 out of the system (aside from environmental issues). 

Thanks a lot for all the responses once again.  Very kind and helpful community here

[oscar]

I think then Freeze12 might be the go.  Might as well try it out first and get your perceptions of it.  Despite having the same systems some people report opposite results for the same gas.  Some w116 owners have canned R134a whilst others have been happy with its performance.  The same will go for Freeze12.  There was one member (can't remember who) that didn't find Freeze12 to work that well but like I said, there's so many variables.  To get the best result, service items need to be replaced, system flushed and evacuated then new gear go in.  That's not what I did.  I took shortcuts for lack of equipment but was happy with the result last year.

Another point about the flammability of hydrocarbons.  My take on the font end or similar collision that would cause an A/C gas to leak is that the gas will vent in a quick jet from wherever the fracture/s occurs in the line and dissipate.  The gas/air ratio needs to be precise to burn and the kind of explosion one would expect form a closed container with the right amont of gas/air mix plus spark isn't going to happen.  If the gas were to hang around in a cloud then ignite it would be a quick burn and wouldn't cause anything else to ignite (apart from spilt fuel perhaps).  Collisions are ok I reckon.  To my mind, the biggest risk would be a car with a leak in a closed space like a small garage.  But again, the gas/air mix would be too diluted to produce an explosive mix, maybe.  I've forgotten my maths and physics. I can't remember what 300grams of gas expands to.  But that kind of scenario would be the biggest threat but also easily dealt with if the garage is vented.

[koan]

My concern about the car "bomb" in an accident would be with the blow up aspect if a front end collision were to occur, not what may happen in the cabin - of course both would be bad but im thinking crash+propane in the system up front from drier, and all other ac related parts = leak + spark or flame = bomb.

Forget the dramatic movie effects of cars exploding if that's the source of your concern, it doesn't happen like that.

Any refrigerant released from a rupture in an accident is going to be gas or liquid that will immediately turn to gas and dissipate quickly. There is chance of ignition of the gas as there is with petrol or oil vapour but no explosion.

Research the risks, everything I've read is about possible ignition of the gas in the cabin, the danger from external leaks or ruptures is so low it receives only passing mention.

It's the car HVAC industry that is paranoid about hydrocarbons, they'll be out of business if the local garage can do their work.

The same gasses are in cigarette lighters, propellants in aerosol cans, BBQ stoves, camping lights and thousands of other things, There's no concerns about explosions from those.  Any bans on HC refrigerants are hard to justify on safety grounds.

koan