i think my A/C needs a recharge. just got this car (94Z w/ 134a) and as far as i know the compressor and everything is good, but no cold air. can i just get a can of the recharge 134a stuff and put it in, and how much should I need? how do you know when enough is enough? should I get the can that has the psi gauge on it (about $19 at Autozone). thx

 

find someone near you with gauges... I would offer mine but im in texas and it may be a bit of a drive for ya.

do you know if the compressor is even kicking on? as is is the clutch in the middle spinning when the motor is running or just the pulley spinnin?

if the clutch is engauged what is you low side pressure? it should be around the area of 35psi. and your high side pressure around 200-250 ish depending on temperature.

start here and let us know.

if you overcharge teh system it wont cool as well.. so keep that in mind.

 

Question: "What do you call those AC recharge cans with gauges on them?"

Answer "A bomb!"

Or so I was told...

Anyway, if the compressor is spinning as mentioned, just fix the leak right the first time. I swear most GM compressors leak through the seals where the piping runs into them.

 

thanks. ok, it looks like one can (18 oz) took me up to about 25 psi. it's blowing cold 44 degrees right now. does that sound about right? hopefully one more can can get me to about 35 psi or should i just leave it be? when clutch disengages psi goes up to about 44psi.

the schrader valve leaks a little itself when the cap isn't on. i think the system had a little pressure in it to begin with.

i'm all for fixing it right the first time, but between me and the old lady we have 5 cars, so this is my beater and if it can't be fixed for $100 or less it just won't have A/C

 

if the schrader valve leaks with no cap its leaking with the cap as well and loosing freon.
replace both schrader valves. and you need the low pressure to be at least 30 psi on a 70+ day as if it is to low it can potentially freeze the system and begin to take out your compressor and seals.
i always shoot for 35 psi here in texas where its around mid to upper 90's later today. anyplace between 30-35psi on the low side is a good place to be.

 

looks like you've got to replace that whole hose just to do the valve. ugh. A/C sucks. thx

 

You don't have to replace the hose to replace the valve. I had a leaking valve last year and replaced the valve core. I think the part was around $10 at Advance Auto.

Check here
http://shbox.com/1/ac_performance_chart.jpg
(Shoebox's web site) for the correct pressure readings at various temp/humidity levels.

 

Like said above replace that valve. You can get it at AutoZone or Advance. It is just like a stem valve on yoru tires unscrews.

 

easy enough. didn't know it had a core. matter of fact i have some regular valve stem cores laying around here somewhere. are they any different than a regular wheel valve stem? thanks

 

They look similar. I think the thread size is different also the seal on the stem could be different to actually seal against the freon. The little kit is real cheap just go pick it up.

Also it is common for the low pressure line that goes by the battery to get worn / corroded and leak there check that also.

Sounds like you have it figured out though.

 

You should also be using the recharge cans that have the PAG oil in them if you are not already. especially since you have a leak. Dont waste your time with a tire valve the seals on them are made of a different compound and will not last that long. You really should have the system vacuumed and refilled since you had a leak. Any moisture in the system can do bad things. Also not having enough or too much oil in the system can mess things up. I know around here you can get a vacuum and recharge for around $100.

 

quick question on this topic... mine blows cold, just not super cold. Would it be worth it to try getting it re-charged? Or could this possibly be the compressor or some other part in the system failing?

Not really worth it to troubleshoot into $200-300 problem.

btw: local texas resident