AC problem

So i recently picked up 381/1000. Car is great except for i knew it needed a recharge for the ac and did so this past weekend. The car takes the charge holds charge with no leaks. Compressor kicks on and off like it should but it wont blow cold. I checked everything i could but to no avail. Im not to good with ac so hoping some one here has ran into the same problem. Any help would be much appriciated.

Pedro

 

[Barnes]

Did you recharge it with r-12? Have you checked the system pressures with a manifold gauge?

 

[DR1665]

Did you have the system charged by a reputable shop or charge yourself?

Put a vac on the system prior to the charge? If you don't have the pressures just right, it won't work. Could be a jacked up expansion valve too.

If the compressor is cycling, then it's a safe bet the temp and pressure switches are good. Also good to know there's no leaks. Sounds like pressure or expansion valve to me, man.

Good luck.

 

Do you know on what line the expansion valve is located ? I filled it my self have done it before with out an issue . Haven't put a gauge on it yet. Thanks for the help so far guys. Driving around in hundred + degree weather and leather seats just isn't fun.

 

ok i located the valve. does anyone know if i can just take the cover off and replace it or do i need to pull the entire assembily out?

 

pull the whole unit out and change the expansion valve. this also lets you remove any dirt and gunk built up in plastic case. if you're doing a r12 to r134a conversion make sure you flush out all the r12 oil with a flush gun + flush fluid (the whole system!)(dont use a flush gun on your compressor). let the A/C compressor sit over night and turn the pulley gently (same direction the engine turns it) to drain all the r12 oil out. r12 and r134 oil does not mix. change all those old o-rings, even if its not leaking right now.

now that your system is exposed to the air, change your dryer. if the dryer is exposed to the atmosphere for more than 30mins, its ruined. why? because there is desiccant inside that removed moisture from your ac system.

if you dont change the dryer your system will have moisture in it which can clog your expansion valve(the moisture turns to ice and gets stuck at the valve).

dont forget to put new r134a oil back in when you're reassembling the system. reload oil in to the system at the compress, dryer, evaporator and condenser. i put a majority of the oil in the compressor for obvious reasons. the r134a oil will absorb moisture, so work semi quickly and keep the cap on your oil containers...

exercise clean conditions and handling! a grain of sand can ruin your compressor.

hope this helps, 1870 runs on r134a now and gets chilly inside /ubbthreads/images/graemlins/smile.gif

 

Thats a big help man thank you. Im going to be doing this after work i hope it doesnt take to long lol.

 

[DR1665]

Quoting geno:

now that your system is exposed to the air, change your dryer. if the dryer is exposed to the atmosphere for more than 30mins, its ruined. why? because there is desiccant inside that removed moisture from your ac system. . . . if you dont change the dryer your system will have moisture in it which can clog your expansion valve(the moisture turns to ice and gets stuck at the valve).



You are absolutely correct on this. However, I don't know if the 30 minute rule is necessarily so critical. I pulled the AC bits off 195/2000 (which had lost all charge after the front end collision) to complete the system on 464/1000. The system was open and exposed to air for the better part of two weeks. Granted, this was in Phoenix, in late summer, but still.

Installed the new o-rings, added the oil, connected everything up, and had a shop test the system for leaks. 220psi nitrogen charge held all day. They put a vac on the system and charged me up with r134. AC blows 45* according to the meat thermometer stuck in the center vents.

I wonder, did the dry, Arizona heat restore the dessicant in the dryer? Does pressurizing the system with nitrogen (inert) force any residual moisture out of the system when a vacuum is then applied?

I am no expert by any means, but from what I found in my research on the subject and in talking to local AC experts, the pressure differential is the heart of the whole system. If it's not just right, you won't get peak cooling.

Appreciate your stepping in to help out. This time of year, AC is super important.

 

it might be 60mins /ubbthreads/images/graemlins/grin.gif.

you're correct, altitude, pressure etc does play a factor.but i think that is when you're filling the system and vacuuming it. but the dryer is only 11.97$ if you are already ordering parts in from rockauto, why not get a new dryer /ubbthreads/images/graemlins/dunno.gif. my dryer from rockauto, when i removed the rubber nipple to put oil it in, it was vacuumed, made a loud hissing noise / sucking in air. scared me to be honest /ubbthreads/images/graemlins/uhh.gif.

Quote:

I am no expert by any means, but from what I found in my research on the subject and in talking to local AC experts, the pressure differential is the heart of the whole system. If it's not just right, you won't get peak cooling.

if my above comment was in no relation to what you ment. i fail at drunk posting.

 

Ok just picked up new dryer and expansion valve. Hope this does the trick. Thanks for everyones help!

 

Well got everything changed out this weekend. Changed out expansion valve and dryer. Not as hard as i thought it was going to be. Recharged the ac and blew cold as ice. To bad i didnt notice the leak at the compressor.( The only 2 seals i didnt change like a moron.) Needless to say it all leaked out. Tonight i change out those two seals and i should be good to go. Thanks for everyones input, it worked like a charm.

 

Ok. So i got the car up in the air, put a small bottle of R134A into the system to see if i can trace where the leak is coming from. The leak isnt coming from the seals like i origninaly thought. On the back side of the compressor there is a copper fitting that sticks out a little more then an inch with a small hole in the middle of it. Like i said before i dont know that much about AC so im not sure what its called. I kinda reminds me of a pressure valve but not sure. Im trying to find out if that part is replacable or if im stuck with the awesome job of replacing the compressor? At this point im upset but still happy i got the AC to finally blow cold. lol.

 

Yes that is the pressure switch. mine blew so i called the dealer they wanted some rediculous price. Went to a u-pull-it and got one for free

 

[Barnes]

Is it an emergency over blow valve? We aren't talking about the high-side pressure switch right?

 

Yeah i actually did the same thing. Went down to our local pick a part and took one off, put it on mine and presto. Cold ac! Thanks again for everyones help.