E21 Air Conditioning

[Thecatmilton]

I am attempting to fix the air conditioning system in my 1982 320i. Is there anything I should replace like the dryer or the expansion valve? How can I tell what air conditioning system I have in my car as I saw somewhere that there were two different systems. I also just bought a vacuum pump and a set of manifold gauges as it was cheaper than taking my car to a shop to have the system evacuated and filled.

[gusm325]

You should always replace the receiver dryer after opening the system, you should also replace every o-ring you mess with and...
Did you check for leaks?
What compressor do you have?
What do you intend to charge it with?

From what I understand the expansion valve is replaced because the assumption is that the compressor "blew up" and there are metal particles everywhere now... If the compressor is ok, you should be able to fire it up and get it working again.
I'm no A/C technician but got mine working "well".

Messing with the A/C could be expensive, if you don't know what has been done by the PO, could cost $$
Or
you can do what I did and go with your gut, throw a bit of gas in it start it and see what happens, you're going to be spending the money anyways if you want it to work.
Post some pics of the compressor...

[Thecatmilton]

How can I tell what compressor I have? Is there any way I can confirm that it works? If my compressor is broken can I get one from a later model car?

[gusm325]

This?


Is "lovingly" referred in the forum as "the brick".
If you search the forum you will find plentiful info

[ash1971]

Gus
Every text book will tell you to replace receiver/dryer after opening the A/C system. That's not true! We use professional A/C machine No PepBoys hoses. 15-25min. Vacuum will do the job. Last week I put a new compressor on Audi TT I only change the compressor it was blowing 36degree on 1500RPM you can't ask for more.
People make mistake a good vacuum is essential.

[Thecatmilton]

Is there any way I can force the compressor to cycle so I know the system is functional before I fill it, also where is the highside port?

[gusm325]

Well do you have the brick?

The brick system did not have a pressure switch to come on. So it will engage empty, the problem is that you will destroy it.
What gas are you getting ready to use?

If you are trying to see if just the clutch engages, connect 12vv to the lead, you'll hear the "clunk", make sure there is a good ground to the compressor.

If you are trying to run the system without gas or oil... Good luck

[Thecatmilton]

I think I have the brick compressor. Does anyone know which one of these valves is the high side and the low side?
valve 1. http://i.imgur.com/DqAkly1.jpg
valve 2. http://i.imgur.com/FwThUIy.png

More pictures of my A/C system are in this link --> http://imgur.com/a/f0mHj#0

[gusm325]

Yep you got the brick.
The one on the hose is the Charge port low, the other one the high.
I have a high side valve on the receiver dryer itself.
I don't know how you are going to connect the high gauge to that port under there.

Connect the low side and see if you got any gas in it.

Nice car!

What is wrong with the A/C not cool enough?

O yep, no belt to the compressor. Nevermind.

[Thecatmilton]

The hose running from the evaporator to the ac dryer was cracked and had lots of rubber missing which I think caused the r134a to leak out. I had a new one made for $28.00 and installed it, but now I am going to attempt to vacuum and recharge the system myself as the tools and r134a are less expensive than taking it to a shop in Dallas. People were quoting me $80 or more just to evacuate the system. The previous owner said he had it converted and that it worked for about a year.

[gusm325]

R134 converted?
Good so the oil in it should work.
Vacuum good and see if it holds vacuum 20 min or so, and then re-charge, should fire back up.

Don't expect miracles, as this system was not meant for R134.

[Thecatmilton]

I was reading that some expansion valves are meant for r134a and that some are meant for r12 and by switching to an r134a expansion valve I can get more performance out of the system. Is this true?

[Layne]

I was reading that some expansion valves are meant for r134a and that some are meant for r12 and by switching to an r134a expansion valve I can get more performance out of the system. Is this true?

Not true. It's the condenser that is a different design, and newer compressors are much better. But the real problem us interior airflow. No known solution for that.

[Thecatmilton]

Does this drier look like the one I need?
http://www.amazon.com/Four-Seasons-3...+320i+ac+drier

[gusm325]

Not true. It's the condenser that is a different design, and newer compressors are much better. But the real problem us interior airflow. No known solution for that.

Layne beat me to it.
Above my pay grade anyway...
Parallel flow right?

I have no idea regarding the expansion valve either.
I put ES12 in there.

Like I said before expensive proposition, marginal results.

I can live with mine, because I love the car, but if it's 110 and I have to run downtown...
Wife's Honda looks great to me.

- - - Updated - - -

Does this drier look like the one I need?
http://www.amazon.com/Four-Seasons-3...+320i+ac+drier

Yup.
Or Rockauto

1982 BMW 320I 1.8L L4 : Heat & Air Conditioning : A/C Receiver Drier / Accumulator	Price
GPD Part # 1411405	$4.87
FOUR SEASONS Part # 33276 Filter Drier	$13.47

[Layne]

Does this drier look like the one I need?

The fittings are various, you'll have to confirm it fits what you have. E21 a/c's are port installed, not at the factory, so there are endless variations.

[Layne]

Gus Every text book will tell you to replace receiver/dryer after opening the A/C system. That's not true!

I only replace it if the system is contaminated, or has sat empty for some time. If freon can come out, moisture can go in. Every e21 I've ever seen has been empty for a decade.

[Thecatmilton]

I have the drier that doesn't have the service port on it. I have a service port behind my compressor that is hard to get to. If I were to buy the four seasons drier that has the service port on it could I use that port instead?

[gusm325]

I have the drier that doesn't have the service port on it. I have a service port behind my compressor that is hard to get to. If I were to buy the four seasons drier that has the service port on it could I use that port instead?

Yes, that would be the "high side", you have the low side on the other hose.

Check locally at O'Reilly's/Autozone/Napa too, it may cost the same total with the shipping from Rockauto and you get to see it first side by side.

I got them from RockAuto and they where fine, but you know, one of them doesn't show the port you need, and sometimes these guys use generic pictures.

- - - Updated - - -

I only replace it if the system is contaminated, or has sat empty for some time. If freon can come out, moisture can go in. Every e21 I've ever seen has been empty for a decade.

Amen to that; $20.00 is not a big deal, I replace it every time I had to open it period.

Not worth the hassle of wasting gas and everything else.

[Thecatmilton]

I am back on repairing my A/C.. Commuting during a 110 degree Texas summer isn't fun anymore. I saw a refrigerant called R12a or HC 12that is a drop in replacement for r12 which is supposed to be better than r134a. I am thinking about buying a case of this stuff as its cheaper that way if I need to do it again. I am probably going to replace every o-ring in the system before I fill it. Does anyone have any experience with the refrigerant I am interested in? Also, does anybody know how much oil the compressor takes and if should I go with PAG or ester oil? The brick compressor is a York mini 206 right?

[Thecatmilton]

Does anybody know the oil viscosity for the York mini 206? I found the capacity but the viscosity isn't mentioned anywhere. Should I just dump the correct amount in of ester oil and hope for the best?

I found some information here. http://www.worldaire.com/pdf/Worldai...ompressors.pdf

[tatersalad]

I am back on repairing my A/C.. Commuting during a 110 degree Texas summer isn't fun anymore. I saw a refrigerant called R12a or HC 12that is a drop in replacement for r12 which is supposed to be better than r134a. I am thinking about buying a case of this stuff as its cheaper that way if I need to do it again. I am probably going to replace every o-ring in the system before I fill it. Does anyone have any experience with the refrigerant I am interested in? Also, does anybody know how much oil the compressor takes and if should I go with PAG or ester oil? The brick compressor is a York mini 206 right?

I've used r12a in a previous vehicle with good results. It was a 1985 VW Westfalia, obviously designed for r12. I didn't want to convert to 134 since everyone said a system designed for r12 would be less effective running 134. The Vanagon A/C system was marginal even when working perfectly, so i wasn't willing to compromise.

The problem you may have, unless you do the work yourself, is finding a shop willing to work with r12a. r12a is propane based, so some shops refuse to use it.

RED-TEK is the brand of r12a I used, and you can buy it form Amazon. I'll probably go with RED-TEK when I get to the point in my project E21 where I am dealing with the A/C. Gotta get it running first.

[Thecatmilton]

I am not going to take my car to a shop to get the A/C fixed. It was cheaper for me to buy all the tools to fix it than the lowest quote I got. I decided to not use the RED-TEK stuff as it seemed too expensive. I found a case of 12 6oz cans of r12a made by envirosafe for $55 on amazon. I decided to go with a case as it was cheaper and I know that I will have to fill it more than once.

Here is a link if anybody is interested: http://www.amazon.com/gp/product/B008WA7E36

[misterguitar]

Just my 2 cents from my own AC experiences on the e21. Make sure the PO did a proper conversion to R134a. IE flushed the system, removed all the old oil, replaced all the orings, schrader valves, and the expansion valve. If the oil was not changed and the system flushed properly it may cause problems. Not changing out the orings will usually cause leaks as the 134a works at higher pressures. It doesn't hurt to replace the old rubber hoses with new ones rated for r134a. The molecules are different sizes so 134as will leak out of the old hoses. As stated by others make sure you replace the drier. Completely vacuum out the system and run the VP for about 30 minutes to an hour to make sure the moisture is all out. Then turn off the pump and let it sit for an hour or so and check to see if the vacuum drops or leaks away. If it does you have a leak. And you will need to get some dye and lamp to find it after charging the system up and letting it run. Then you have to fix the leak. Charge the system by weight. Not by gage pressure. I use a small grams scale I got at harbor freight for doing this. I don't know the weights of the charge off my head but I do know the Haynes AC systems book has it in its tables. I personally would avoid all the refrigerant mixes. It makes service charges later harder. Because they are a mix the lighter particles will leak out faster throwing of the proportionality of the mix of refrigerants. So to keep the right performance you have to completely drain the system and refill instead of just adding a charge. In addition many of these mixes are not legal or contain explosive hydrocarbons. not a good combination if you have old leaky hoses. My lifetime experience on Car AC systems is there is no "cheap" or "easy" fix. You either pay for it in tools or pay for somebody's tools and know how. And if you cut corners it will cost you even more in the future to fix. Been there, done that, got a T-Shirt! It is why I'm taking the AC out of my e-21!

[Thecatmilton]

I am replacing all the o rings, replacing the drier, changing the compressor oil (using ester), and pulling a vacuum before I fill the system. I have the tools so fixing A/C should be cheap now.