AC issues
Legend
Joined: Jul 2011
Posts: 8,259
Likes: 4
From: Austin, TX
Use the vacuum pump and get a gauge set. When you put it back together did you get new o-rings? If not go ahead and take it back apart and put in new o-rings. You'll need to coat them in PAG oil. I'm not sure what weight our trucks use. Once it's vacuumed down and holding vacuum for a while go ahead and start charging the ac while the truck isn't running. It'll take some r134 but not a whole lot. Should be enough to at least get the compressor to kick on. Then start it up and turn it to max and blower speed up all the way. Then charge it up to the proper pressures or amount. You can buy little cans of u/v dye that you can put into the low side port also. Then if there is a leak it makes it much easier to track them down. It is recommended anytime you open up the system you replace the receiver/drier.
+1 on this. The vacuum pump you linked is excellent for a home garage...The only way to do it correctly is what is mentioned here. I usually (provided I have time) pull a vacuum and let it sit overnight or at least several hours to make sure it will hold. If it holds overnight, it will NOT leak out! You can get by without gauges as some refill kits (recommended) will have a gauge to keep you from overfilling, but HVAC gauges are the only way to be assured that vacuum is good. May be able to borrow from parts store. Alsdo with R 134a, you will need refrigerant oil as weel for compressor. Similar can, usually mixed with refiorgerant for proper amount. Look at can. I think these units use about 32 oz, but you can check manual to be sure.
Also, the valves on these are not the best. Check for seal at the valve, the cap will NOT resolve leaky valve.
Registered User
Joined: Jun 2012
Posts: 22
Likes: 0
Gentlemen,
I am also chasing AC problems. When I first bought the truck a few weeks back the AC blew cooler than ambient, but not really cold. Then it had an oil leak from the valve covers and the truck didn't run for a few weeks. I finally got it running today and noticed the AC compressor will no longer kick on at all.
I am going to try a simple recharge first. But I'm curious, how does the compressor know you are low on refrigerant to tell the clutch not to engage? If I jumper the relay while I'm low on refrigerant will that bypass the low gas kill?
Eddie
I am also chasing AC problems. When I first bought the truck a few weeks back the AC blew cooler than ambient, but not really cold. Then it had an oil leak from the valve covers and the truck didn't run for a few weeks. I finally got it running today and noticed the AC compressor will no longer kick on at all.
I am going to try a simple recharge first. But I'm curious, how does the compressor know you are low on refrigerant to tell the clutch not to engage? If I jumper the relay while I'm low on refrigerant will that bypass the low gas kill?
Eddie
Legend
Joined: Jul 2011
Posts: 8,259
Likes: 4
From: Austin, TX
There are 2 pressure switches in the refrigerant system. One is a low pressure cut off (to keep compressor from running on empty) and another for high pressure cut off (to keep from blowing system up).
Administrator
Joined: Apr 2010
Posts: 87,419
Likes: 4,214
From: Clayton MI
Jumping the relay should make it run, yes. If it is REALLY low, it won't get the lubrication it requires, so, don't run it for more than a few seconds that way...... unless you want to buy a new one. 