Search found 193 matches

by GM Tech
Sun May 21, 2017 8:31 am
Forum: Automotive Air Conditioning Forum
Topic: 1998 Chevy K2500 5.7L
Replies: 4
Views: 6305

Re: 1998 Chevy K2500 5.7L

Cycling is dependent on heat load across evaporator- so to see it cycle, open hood, reduce blower motor speed to lowest speed and make sure it is on recirc air inside- wait about 10 minutes- it should cycle eventually.
by GM Tech
Sat May 20, 2017 8:45 pm
Forum: Automotive Air Conditioning Forum
Topic: Oil for seals?
Replies: 4
Views: 6852

Re: Oil for seals?

I worked for Delphi- the compressor supplier to GM for many years- we always used mineral oil on all o-ring joints and threaded connection- with both R-12 and R134a applications. The assembly plants did likewise. The small amount used would never cause an issue with the integrity of a 134a system. H...
by GM Tech
Sat May 20, 2017 8:39 pm
Forum: Automotive Air Conditioning Forum
Topic: 1998 Chevy K2500 5.7L
Replies: 4
Views: 6305

Re: 1998 Chevy K2500 5.7L

Uhm- that would be the high pressure cut-out switch- that will shut down the compressor at 425 psi head pressure to avoid blowing the pressure relief valve at 500 psi. It is a normally closed switch, system will not run without it plugged in- it opens upon high pressure and closes again at about 250...
by GM Tech
Sat May 20, 2017 4:38 am
Forum: Automotive Air Conditioning Forum
Topic: Oil for seals?
Replies: 4
Views: 6852

Re: Oil for seals?

I use mineral oil- have for 30 years- with no issues.
by GM Tech
Thu May 04, 2017 5:09 pm
Forum: Automotive Air Conditioning Forum
Topic: 2002 GMC Sierra 5.3 AC wont stay on
Replies: 2
Views: 4959

Re: 2002 GMC Sierra 5.3 AC wont stay on

What you describe is a very common failure mode- next time it quits cooling when you know it should be on, let engine running, pop hood and look at front of compressor, is it turning? Here is a cut and paste from previous post like yours Next time it is blowing hot and it should be cool-- stop, pull...
by GM Tech
Thu Mar 23, 2017 5:30 am
Forum: Automotive Air Conditioning Forum
Topic: 07 Chevy HHR Low Side Service Port
Replies: 4
Views: 7558

Re: 07 Chevy HHR Low Side Service Port

Does it show the leak with the cap on? To test my leak detector- I take the cap off.
by GM Tech
Sun Mar 19, 2017 2:22 pm
Forum: Automotive Air Conditioning Forum
Topic: Ford F-250 A/C blows cold then hot
Replies: 3
Views: 6133

Re: Ford F-250 A/C blows cold then hot

Is compressor nose (front end) turning when it starts blowing hot?
by GM Tech
Sun Mar 05, 2017 9:15 am
Forum: Automotive Air Conditioning Forum
Topic: Stumped - incessant cycling and pressures all out of whack (video included)
Replies: 3
Views: 6476

Re: Stumped - incessant cycling and pressures all out of whack (video included)

Keep in mind, that a a/c system with a variable stroke compressor that cycles frequently is because of of high pressure cut-outs- most likely- high head pressure is usually due to lack of air flow through condenser, or blocked condenser, --so do your cooling fans work? - your head pressure you see o...
by GM Tech
Wed Dec 07, 2016 6:40 am
Forum: Automotive Air Conditioning Forum
Topic: Lack of pag oil in compressor
Replies: 8
Views: 11474

Re: Lack of pag oil in compressor

On V-7 variable displacement compressors as is yours- oil should be drained/added through the oil drain bolt/plug on the side of the compressor. There are three pressure zones, suction, discharge, and crankcase- there is at any given time a reservoir of 3 fl ozs in the crankcase. Your new compressor...
by GM Tech
Wed Oct 12, 2016 5:54 pm
Forum: Automotive Air Conditioning Forum
Topic: 2011 Ram Compressor not kicking on
Replies: 9
Views: 15258

Re: 2011 Ram Compressor not kicking on

you have about 5% of needed refrigerant in your system--- find your leak..fcix it, evacuate and recharge to factory spec compressor will come on when you put in the right amount of refrigerant.