A/C Squeal

[Anonymous]

I hope to return to this problem now that I am close to having the suspension/header problems worked out. It's hot in the swamp.

I had a Sanden aftermarket unit installed back when the 170 was in the car. Since I only had the single groove they ran the alt off the second groove on the compressor. I was always tightning the belt to stop the compressor from squealing. It wasn't long before I developed problems with the 170 and embarked on the 200/c5/oz head one thing leads to another neverending journey. As the 200 had 3 grooves I just knew running two belts around the compressor/alt would solve the squeal. It didn't, I have tightned the belts 3 or 4 times and am now at the length of the adjustment.

We have thought about running seperate belts to achieve a better angle, but it seems that it should work as is. I know many of these units are installed in my original configuration and must work. Is it possible there is a problem with the compressor making it too hard to turn? It cools well.

My compressor is below the alternator and the belts run in basically a rounded square design.

I have always used Gates belts.

Any suggestions???

 

[Anonymous]

The belts may not be "gripping" enough of the pulley groove. They should be contacting at least half to transmit the power properley. There isn't much you can do about that now though. All you can do is put a bigger diameter pulley on the commpessor. Another posibility is that what you are hearing is the clutch slipping. Was the compressor new when you bought it?

 

[Anonymous]

It was installed new and the belt was catching more of the pully in the original setup as that was a triangle shape and this is more square. I had the same problem then, it wasn't as bad as now, at least it went longer between tightnings and the A/C was driving the alt. We can rework the adaptor plate so that one belt is on the a/c and one is on the alt. I hadn't thought about a bigger pulley.

Just wondering what the configuration is on those of you who have stock or aftermarket?

Thanks

 

[Anonymous]

I have an aftermarket ac where the main belt drives the ac and another belt from the ac to the alternator above the compressor. New belts are needed every year and the belts need to be very tight in order to keep out the squeel. The 200ci doesn't have the same power as larger engines and the compressor engaged puts a big strain on the engine.try a new belt and get help in tightening the belts.

 

[Anonymous]

So it seems the setup necessitated by the single pulley design is marginal. I will try giving each their own belt, hopefully the combination of increased belt contact on the a/c and not having to pull the alt off the a/c will be enough.

Thanks for the reply
Don

 

[Anonymous]

Your belt noise might be a symptom of poor pulley alignment. I always had a nasty "chopping" bearing noise from the A/C compressor. Even after i had a new bearing put in at great expense. In the process of my engine rebuild i mocked up the A/C, alternator and power steering on the engine stand. Check with a straight edge. Mine was about 1/4 inch too far back and causing a thrust load on the bearing. Have a very good look at your pulley alignment. It's gotta be perfect. You can slot the holes in the Compressor bracket. If you do that at least use thread locker and a spring washer. I welded the slots up on mine and hand filed until it was right. Hard work but it will not move. Good luck. A/C makes an old car more comfortable.

I have a few ideas about using hydrocarbon (propane/isobutane/butane) mix for a/c, it is non-toxic, zero ozone effect, a 1 year atmosphere life. It's also dirt cheap and more efficient than both R12 (freon) and R134a. A true drop in replacement for those nasty chemicals. It is non-corrosive and perfectly miscible with both PAG and natural oils. As for the fire risk, there is about 300grams of it in the system (you use only a third compared to traditional refrigerants) meanwhile you got 60 litres of hydrocarbon in the boot.... All refrigerants are required to have oil finely misted within it, it's what lubricates the whole system especially the compressor. A rupture of the evaporator (inside the car) even with a non-flamable (but toxic) refrigerant still poses the risk of the fine oil spray igniting. Non-flamable oil, I don't think it exists.

Any thoughts/ideas appreciated. I have made a vacum pump from a fridge compressor, pulls down to 28inches of mercury at 1000 feet above sea level. It already had a r12 compatible schraeder valve, too easy.

Dom

Dom.