AC Question - 99 Suburban

[Zembonez]

Friend has a 99 Suburban with 80K on it. It's a typical 1/2 ton 2WD 350/AT Burb with front and rear air. It's in excellent condition and very well cared for.

Problem is:

At random times the AC will not come on no matter what setting. Blower functions fine but no compressor engagement. If you drive a couple of blocks, it kicks in and works perfectly for however long you drive it. Next time you get in and drive again, it might work right off.. and it might not. I thought it was the typical low pressure switch issue, so I replaced it for him... but the symptoms remain. Compressor sounds great and the system is fully charged.

Anybody have any input?

 

[txab]

Check the air gap on the clutch for proper gap. If it's too wide it has a hard time pulling it in. While engine is running, if you can safely tap on the clutch with something and it pulls in that's a good sign the clutch gap is too wide

 

[Alljackedup408]

Check the air gap on the clutch for proper gap. If it's too wide it has a hard time pulling it in. While engine is running, if you can safely tap on the clutch with something and it pulls in that's a good sign the clutch gap is too wide

+1

 

[Alljackedup408]

the gap if too close could be causing drag on the compressor and shutting it off.. or the gap could be too big until it warms up and is able to grab it.

 

[Zembonez]

Odd thing is that sometimes after driving for an hour and let's say you stop for gas... it might not come back on for half a mile when you restart. After that it operates perfectly until the next random time it decides not to work. Other times it comes on and works fine for several weeks... then starts this crap again at random. The only time it acts up is just after you start the truck either hot or cold.

 

[Zembonez]

UPDATE.

He started the truck. AC would not come on. Tapped on the compressor clutch and BINGO the thing engaged immediately.

SO...

How do I adjust the clutch gap?

 

[PenguinLTZ]

UPDATE.

He started the truck. AC would not come on. Tapped on the compressor clutch and BINGO the thing engaged immediately.

SO...

How do I adjust the clutch gap?

Jim do you have an A/C clutch service kit?

There is a press tool to install the outer clutch and set the gap. I would pull it and inspect anyway...

 

[PenguinLTZ]

Here you go, Jim. I found this:

http://flashoffroad.com/Maintenance/hvac/airconditioning/clutchPullyService.htm

 

[Zembonez]

Is the clutch removable with the system charged?

 

[PenguinLTZ]

Is the clutch removable with the system charged?

Yep, no problem.