A/C problem

[powerstroke_n]

I've got a 00 CC Dually and was wondering if anyone tell me what controls the engaging and releasing of A/C clutch. Could it be one of the relays in the PDB if so which one. I just pulled a vacuum on the system last weekend and filled it back up. The problem I'm having is when I first turn it on it cools fine but after about 15-20 minutes the clutch kicks out. I've noticed when it does this I can stop somewhere for a bit if I'm out and about get back in and it works but not but for about 5-10 minutes. I'm just wondering if it's a relay thats getting hot for some reason and dropping out. If not a relay what other reason could it be. Happens like this every time. Any info anyone could give would be appreciated.

[powerstroke_n]

I got this info from a member on another site and it worked. Maybe it will help other members out as well.

You have a classic case of the air gap in your compressor having worn too wide.

Try this to test:

Turn on the A/C and run it until the clutch won't re-engage. Be REAL CAREFUL now! Take a plastic screwdriver handle and "tap" the end of the (not spinning) clutch. Does it immediately engage and operate normally until it next cycles off, and then won't re-engage on its own?

If so:

Get out your feeler gauges, or your calibrated eyeballs, and determine that the air gap is about .050" to .060" (fifty or sixty thousandths). That's too much! It's supposed to be around .030. But wait! There's no need to replace the compressor and have to re-charge the system. There's a "dirt-cheap" fix!

See the little bolt right in the middle of the compressor shaft? Take it out. You won't be letting any Freon out. Pull the clutch plate straight out. There is one or more "shims" that look like small washers in there, either on the end of the shaft or down in the hole that fits on the shaft. Take off about .030" worth of them and reassemble. Go ahead, use a little blue (NOT green!) Loctite on the bolt as insurance.

Make sure you now have at least .025" of gap. Start the engine and check to insure your problem is gone.

That's all there is to it.

[NoRalPh]

Nice Tip! - Thx