Ac Question On 99 Chevy Suburban

Zembonez · August 8, 2009

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.

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?

96chevy7.4L · August 8, 2009

The air gap in the clutch on the ac compressor might be increasing with age. Next time it won't kick on and get cold tap the front of the AC clutch with a mallet or piece of wood and see if the clutch engages. DON"T USE YOUR FIST. It must be done with the engine running and the AC on high. Let us know if this helps.

txab · August 8, 2009

^^^ Beat me to it.

+1

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 and it pulls in that's a good sign the clutch gap is too wide

Zembonez · August 8, 2009

^^^ Beat me to it.

+1

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 and it pulls in that's a good sign the clutch gap is too wide

I'll check it out. Thanks guys.

Spurshot · August 9, 2009

Jim,

I'm not sure on the 350 if the compressor is low on the pax side, but if it is, the easiest access to adjust the clutch is from under the front. Kragen and Autozone may rent the tool. Otherwise this is your big chance to own some more tools. I recently bought the MasterCool clutch set.

ACkits.com is where I bought it. They have a great forum on the A/C subject as well. Took just a few minutes to adjust my 99 recently.

Zembonez · August 9, 2009

Jim,
I'm not sure on the 350 if the compressor is low on the pax side, but if it is, the easiest access to adjust the clutch is from under the front. Kragen and Autozone may rent the tool. Otherwise this is your big chance to own some more tools. I recently bought the MasterCool clutch set.

ACkits.com is where I bought it. They have a great forum on the A/C subject as well. Took just a few minutes to adjust my 99 recently.

Compressor on this one sits right up on top and is the first thing you see when you open the hood. Easy access. I'm going to investigate the clutch this next week for him.

Thanks everybody.