Search found 109 matches

by GM Tech
Sat May 27, 2017 6:21 pm
Forum: Automotive Air Conditioning Forum
Topic: 95 Chevy G20
Replies: 2
Views: 13

Re: 95 Chevy G20

The connection you have pictured is the "upfitters" connection- the panel van came from the factory with front air only and a dead-head connection for the "upfitter's" conection to screw into. You see, the factory sold the panel van to an "Upfitter" or conversion compan...
by GM Tech
Sat May 27, 2017 6:05 pm
Forum: Automotive Air Conditioning Forum
Topic: Pressure testing
Replies: 1
Views: 10

Re: Pressure testing

The best way to leak test is with a sniffer and UV dye- You can add a couple ounces of refrigerant to up the pressure to 80 psi or so-- the dye will tell you where it leaks- just not when it leaks- which is a good thing. Dodge trucks of your era are famous for evaporator leaks- so a sniffer in the v...
by GM Tech
Fri May 26, 2017 6:44 pm
Forum: Automotive Air Conditioning Forum
Topic: Frustrating 2010 Jeep Grand with 5.7
Replies: 7
Views: 52

Re: Frustrating 2010 Jeep Grand with 5.7

Vacuum is the absence of atmospheric pressure- so it can only be that with no atmospheric pressure- it can vary based on sea level...as does the atmospheric pressure
by GM Tech
Thu May 25, 2017 1:24 pm
Forum: Automotive Air Conditioning Forum
Topic: Magnetic clutch not engaging in 2009 Altima
Replies: 6
Views: 55

Re: Magnetic clutch not engaging in 2009 Altima

You can put the gage on the car- if it reads less then 47 psi with engine off and it is above 70 degrees out- then you have an extremely low charge issue- compressor should come on when pressure builds when you add refrigerant- just that you don't know how much to add- and if gage reads zero psi- yo...
by GM Tech
Thu May 25, 2017 11:26 am
Forum: Automotive Air Conditioning Forum
Topic: Frustrating 2010 Jeep Grand with 5.7
Replies: 7
Views: 52

Re: Frustrating 2010 Jeep Grand with 5.7

You are trying to leak test- based on the assumption it leaks constantly! Leaks can be like farts- intermittent. So that is why I use the dye- it does not care when it leaks- but will show you where it leaked- works great. You can buy it and the UV light at your local discount auto store.
by GM Tech
Mon May 22, 2017 12:46 pm
Forum: Automotive Air Conditioning Forum
Topic: 99 Suburban Rear Evap Help
Replies: 2
Views: 35

Re: 99 Suburban Rear Evap Help

Rear lines usually leak at the grommets that hold them in place- most likely near wheel where the rear wheel throws salt and debris. Corrosion takes place- 9 times out of ten, it is the 3/8 liquid line that leaks. Those lines can be fixed- cut the bad part out and use a swagelok connector to rejoin ...
by GM Tech
Sun May 21, 2017 8:31 am
Forum: Automotive Air Conditioning Forum
Topic: 1998 Chevy K2500 5.7L
Replies: 4
Views: 50

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: 61

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: 50

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: 61

Re: Oil for seals?

I use mineral oil- have for 30 years- with no issues.

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