Air conditioner issues

[vr2jetta]

I am trying to get the a/c working after installing the new head. The PO deemed it necessary to remove the condensor coil to remove the head and swore the a/c worked before dis-assembly. I think I may have a leak, but when I charged the system the small line running down the fender is getting ice cold and frosting. Is this supposed to be the high (hot) side. I thought the line that was supposed to get cold was the big line that you charge the system from. Does anybody have working a/c that can help me. I tried searching but all I came up with was how to remove the a/c, and since I live in Fl. that is NOT an option. Has anybody changed the expansion valve? Is it terribly difficult? I read the Chilton (I know, I know, get a Bentley) and it said it was under the dash.

[twright]

Changing the expansion valve (and evaporator) is not too bad of a job. It took me about two hours.

Have you put a gage on it to see if you have enough R134 in it?

[vr2jetta]

I have, but my filler/gauge is kinda old and beat up, so I am not sure if it is accurate. Without a bottle on it the needle sets at 25. I filled it to 70 the other day and it started blowing cold but got hot when the car stopped moving, but I figured it was due to the fact the aux. fan didnt work. I replaced to fan yesterday and went to fill it back up and when I put the filler/gauge on it, it read 25 again, so I filled it to 40, but the small line going down the fender into the passenger compartment was icing over. I know one line is supposed to get icy but it has been so long since Ive had working a/c in a car I forget which one. I put some r-134 with leak detector dye and I am pretty sure I have a small leak at the compressor but still has 134 in it, probably not enough though. I have a buddy that removed his a/c so I might go get his or call the parts store and see if I can just get the o-rings. I just dont want to over-fill it.

[F200]

I think the stock low pressure switch opens between 30 and 35psi. If your dropping to 25psi your compressor wont get power. Better fix that leak first.

[vr2jetta]

I called the parts store and they list about 6 different sizes for the o-rings on the compressor, but can anybody with a working a/c tell me which line gets cold and which one gets hot?

[jlevie]

The smaller line is the high pressure side and should not be cold.

[vr2jetta]

Thats what I thought but I wanted to make sure. I havent had working a/c in a car in 6 years, but I just moved back to Fl. from Ohio and have a family now so working a/c is kinda new to me. Could it be possible I over-charged the system, or maybe the expansion valve is clogged? Either way I am going to change the expansion valve, maybe even buy a new gauge, or maybe just buy the bottle with the gauge built in. I did manage to pull the o-rings on the compressor so now I can have them matched up and replaced.

[vr2jetta]

I ordered new o-rings and expansion valve today, and also bought one of those R134 cans with the gauge built in, so tomorrow I will change all that crap and hopefully it will be cool....no pun intended. LOL!

[vr2jetta]

Well, I installed the expansion valve and replaced the o-rings in the compressor, went to fill it up with freon and still have the same fuckin' problem, the small line along side the fender is freezing up and my gauge is only reading about 20 lbs. It took about 1 1/4 can of freon and wont take anymore and the air blowing through the vents is not cold. I guess I am not allowed to have working a/c!! This fuckin' sucks!! Looks like I will be taking it to a shop and paying them like, $600 to fix the fuckin' thing!!

[jmc1590]

Just out of curiosity, did you use the R134 that you bought or freon (R-12)? Most (if not all) of the 80's model vehicles have an R-12 A/C compressor. (At least both of mine did.) I tried to do the R134 conversion on one, and it failed. Badly.

Considering the other things you've had to work on with the car, I would consider the fact that the A/C may not have worked for quite some time. Were the lines disconnected for an extended period? Was there any pressure in the system? If disconnected, or no pressure, consider the fact that your dryer is probably shot. Good news is that a replacement is less than $30.

Other things to look at... Does the magnetic clutch engage when you active the system? Does the Aux fan kick in?

Could also be the compressor, but we won't go there right now...

[F200]

Look close at the line that is freezing up. It could be leaking and the escaping freon is causing it to freeze. Is you system holding pressure overnight?

[vr2jetta]

I used r-134, the low side line had a retro-fit fitting on it all ready. The guy I bought it from said the a/c worked when he took it apart, but who knows if that is true or not. The lines were dis-connected when I got the car too, for how long....I couldnt tell you. The dryer does look a little old, and if the system was open for a while I guess moisture got all in the system. The compressor does turn on. The fan didnt work when I got the car, but I have since replaced it with a used unit. Sorry about the bitch-fest earlier but I am just pissed about all the money I am putting into the car trying to get it to run right and the a/c to work when I am taking my family on vacation next week, to Orlando none the less, and I just dont want the wife and kids to be sweating balls.

[vr2jetta]

Look close at the line that is freezing up. It could be leaking and the escaping freon is causing it to freeze. Is you system holding pressure overnight?

The entire line is freezing from the dryer all the way to the where it goes into the passenger compartment. I havent checked if it is holding pressure overnight, but I did add leak detector r134 and discovered it leaking at the compressor. I changed the o rings and now I am here.

[jlevie]

If the system was open for a while, you can't simply recharge it. The dryer must be replaced if the system was open even briefly and since it was open for a while it needs to be held under vacuum for a while to pull out any water that has gotten in.

I think that your best course of action (if you don't have a proper gauge set, vacuum pump, and recovery system) would be to have the A/C system inspected, repaired, and charged by a competent auto A/C tech.

[vr2jetta]

I think that your best course of action (if you don't have a proper gauge set, vacuum pump, and recovery system) would be to have the A/C system inspected, repaired, and charged by a competent auto A/C tech.

I think you are right. I am tired of fucking with it anyway. Besides, auto a/c is not my strong suit to begin with. I will probably change the dryer, and then take it to a shop to be filled. Thanks guys!