90 GT, 5spd. A/C system was converted to R-134a by previous owner, was never cold since I owned it (a few months) . I replaced O-rings in the liquid line I found that were leaking. I did not vacuum out the system like I should have cause it was pretty much empty. Recharged system. Not blowing cold. Found cool/heat cable for blend door was seized, blend door moving fine fixed that still not cold. Re checked for new leaks and all good. Clutch engages and disengages. All fan speeds work, all defrost, dash vent and floor vents work as they should. NOTE: heater core has no hoses because it leaks. Core still there but hoses gone (previous owner). Checked and rechecked all vacuum lines. Checked pressure with gauges AGAIN, still holding. A friend said to vacuum the system and recharge as I could have an air pocket in the line?. My last attempt is to have one of you throw some wisdom at me before I pay for a shop. Thanks.
A/C Issues
- Thread starter Boats90GT
- Start date
Well, you have to vacuum the system down. If you filled it at atmospheric pressure, you have a charge that includes a lot of air and won't cool at all.
You are going to have to put a vac pump on it and vacuum it for a LOOONG time if this is the case. Likely a lot of moisture in the system now and you'll need a deep long vacuum to get rid of most of that.
You want to pull to 500 microns, but unfortunately micron gauges are expensive so not everyone will have one. But from experience, on a new system it took me almost 24 hours to pull out all the moisture and get down to around 500-1000 microns.
So if you have a cheap harbor freight pump, just put it on the system and let it pull vac as long as you can possibly tolerate. The longer you pull a vac, the better the result will be in terms of longevity and performance. Then recharge and see what happens.
You are going to have to put a vac pump on it and vacuum it for a LOOONG time if this is the case. Likely a lot of moisture in the system now and you'll need a deep long vacuum to get rid of most of that.
You want to pull to 500 microns, but unfortunately micron gauges are expensive so not everyone will have one. But from experience, on a new system it took me almost 24 hours to pull out all the moisture and get down to around 500-1000 microns.
So if you have a cheap harbor freight pump, just put it on the system and let it pull vac as long as you can possibly tolerate. The longer you pull a vac, the better the result will be in terms of longevity and performance. Then recharge and see what happens.
Mcmahst
5 Year Member
It might pay dividends down the road if you replace the receiver/dryer prior to the recommended vacuum process. It’s likely your stock one is the original and no telling how much junk is already in it. They are not expensive and you can do it. Also, when you first start the vacuum process, pull the vacuum and then turn the system off to verify you have no leaks before proceeding. Good luck.
Similar threads
