2001 gmc sierra a/c saga

[gmcjack]

Hello Everyone!

 

I hope someone can help me with a very perplexing a/c problem. I am the original owner of this vehicle w/ 244K. I try to keep it well maintained. I hardly do any of my own work anymore, but if something needs repair or replace I get it done. Now to my problem.

 

I drive my truck in the mornings to the Orlando area about 50 miles or so one way. The A/C works perfect on the 1st drive every time. After another stop or 2 down there I usually drive back home to my office. Most of the time now, when I get back in to drive home, after the 2nd or 3rd location, the A/C will blow warm and/or hot almost all the way home. Sometimes it get cold again after 15-20 minutes.

 

These are the repairs and things I have Had replaced lately:

 

• Checked for leaks w/ dye 3x
• Have replaced High Pressure hose, they said was leaking
• Have had high and low pressure fittings replaced, they said was leaking
• I have replaced the 3 dial climate control myself.
• I even went to a GMC dealer who replaced my air blend door, and it still did that same thing again today after about 50-60 miles and a couple of stops before coming home.

I have an excellent cooling system with no leaks and run 100% coolant.

I am totally frustrated.

 

DOES ANYONE HAVE ANY SUGGESTIONS! I DON'T WANT TO GET ANOTHER TRUCK, I JUST WANT MY OLD GIRL'S A/C FIXED

 

THANKS FOR ANY IDEAS

GMC JACK

[O_J_Simpson]

Post your pressures and temps when it starts to act up. How is your fan clutch when acting up? What happens when you by-pass the low pressure switch?

[gmcjack]

i dont do any of this work, i rely on mechanics, thanks!

i might be able to by past the low pressure switch myself. how do you do that

i am somewhat handy, just not an a/c guy. im a telephone man LOL

[gmcjack]

i just checked and i see there is a brand new low pressure switch already hmmmmmmmmmmm.

[Dnt]

sounds like a worn compressor clutch. The gap is too wide for the electromagnet to pull it in consistently. Common problem most can actually be reshimmed and work fine for years but the dealerships and most AC shops want to replace the entire compressor. Next time you catch it not cooling get your self a long large screwdriver and smack the chit out of the clutch on the front of the compressor and see if it engages, if so then you can either try to reshim the clutch (takes a special puller tool to pull the clutch) or replace the entire compressor unit, which is probably more practical for most people that do not have the tools or skill set.

[O_J_Simpson]

i dont do any of this work, i rely on mechanics, thanks!

 

i might be able to by past the low pressure switch myself. how do you do that

 

i am somewhat handy, just not an a/c guy. im a telephone man LOL

Run Run Run! Mechanics just change parts and collect your money. A real technician will diagnose the problem and fix it for much cheaper than a parts changer.

[barry G]

I agree on the clutch check.

 

when the system is real good, the scavenge line gets ice cold..and wet.

Pump gets sloppy, not tighter...even wets the switches at the pump.

it is an odd opposite of reason to diagnose.

 

the other weird gadget is the filter at the condenser. It does something with the gas.

if those lose a little chunk, a quick squirt with a screw driver on the high side port will let it out.

it likes to travel.

[gmcjack]

thanks OJ, Barry and Darryl for those excellent suggestions. One of the challenges of this is finding a "real" technician who will "listen" to what my symptoms are.

stay tuned!

[muddkatt]

Had the same issue on my 01 Sierra with nearly 300K miles at that time. Replaced the compressor due to clutch issues.

[avmech]

240,000 on my 03, clutch way large gap, being replaced this week. Exact same symptoms, great in the morning, warm after a while and during the day. South Florida