Long story short, My A/C hasn't been charged for a while so I bought a used compressor that was "tested" and "good". Installed it, replaced my h-block and vac the system down to 25. I put a little freon in till the switch activated and then put guages on and continued filling the system. I am reading 30 on the low side and 250 on the highside at 95 degrees. The Air is cool but not cold. I think that there is too much of a split but here is the problem. At the current pressures at idle the belt won't quit squeeling going down the road it will stop unless at a stoplight or stop sign. If I try to add any more freon it squeals all the time. I was looking at the compressor pulley and when it starts squealing the compressor slows down and on ocassion will completly stop spinning.
Is my compressor going out? I have a new belt already and it is not a cheap one.

 

Did you put in the correct amount of freon? There is a tag located on top of your radiator brace that will tell the correct amount to put in. Putting in freon with just using the gauges will not give you the correct amount. Did you make sure that the used compressor had any oil in it before install? Usually overfilling the system will cause the compressor to stop turning or you may have a defective compressor. Clutches are the number one reason that causes squealing, it is usually just partly engaging. You should have around .025-.030 clutch clearance, between the plate and pulley. It is always better to get a new compressor and air drier to install instead of a used one. Used compressors might show good but a person does not know how many miles were on that particular vehicle that it was taken off of.

 

Ok I can't get the proper ammount of freon in without the compressor locking down. As far as the oil. It was serviced and the system has the right ammount of oil, I double checked that when I first started having the problem. I will have to check on the clutch clearance. How do I measure that. I did install a new drier.

 

IIRC, you can use a regular ruler to check the clearance. Place the ruler against a hard surface close to the midpoint of the belt you want to measure. Record where the outside of the belt touches the ruler, push down on the belt and record the difference. That's the clearance or deflection of the belt. HTH.

 

dan i believe he is referring to the clutch clearance inside the A/C pulley(between the inside edge and the clutch when disengaged), you could try and measure it with a set of verneer (i believe) calipers, or feeler gauges should do the trick too

 

In that case, I apologize for any mistakes I made.

 

thats ok dan, you just told us how to measure belt stretch, although the tensioner pulley should take up all of that

 

Sometimes the pulley gives out...

 

that is true, the pulley can go bad too

 

I knew I was kinda right!