A/C belt slipping

[Robert B.]

I can't seem to find a solution to belt slippage when I run A/C in warm (hot) weather on my 67 427/390 coupe. I've tried tightening A/C belt, PS belt, Alternator belt to no avail. I then replaced all of the belts - but still get belt squeal when the compresssor is running. I think the real culprit is the water pump belt which has no adjustment. Would appreciate any advice/recommendations.

[Chas Henderson #28127]

Re: A/C belt slipping

Are you sure the compressor isn't locking up?

Chasman

[Robert B.]

Re: A/C belt slipping

No, the compressor is fine - in fact it was just replaced and it rotates freely. The system cools OK, but can't eliminate the belt slipping.

Actually, I have two 67 427/390 cars with factory air - same problem on both of them. I assume it must be a generic problem.

[Wayne W.]

Re: A/C belt slipping

It is probably the inner pully belt. That one is a problem to get tight enough. Another problem is that modern belts have metric dimensions and are not a direct replacement so experiment is necessary on the size. I get several belts near the correct size, shorter to longer, and try to get one that I can shoe horn on there tight. The method is to install the belt into the V with the upper pully off and pry up while sliding the upper pully on. This allows you to get some tension on the belt.

[Chris C.]

Re: A/C belt slipping

Just a couple things that I would look at solve your problem: check to make sure you don't have too much oil or freon in your compressor as this can slow down the rotation while driving with the a/c running (been there, done that), you may have to empty compressor of all oil and start from scratch with the correct amount of compressor oil and freon. Second you need to make sure your upper pully has the proper reinforcement installed between the waterpump and your upper pully (see long island catalog section 24 part 27k), if its not there it throws the belt alignment off just a bit.

[Kenneth S.]

[Robert B.]

Re: A/C belt slipping

The belt I'm using is also from Quanta - your solution makes sense - any problems in mounting the belt?

Bob

[Kenneth S.]