I have a 1987 that the po installed a new copressor and converted to 134a. Does the compressor make noise when it is low on feon? Mine is making a rattling noise and is short cycling. Should I add freon. I think this is causing my cooling fan to not come on also.

Tanks

 

The R4 compressor is noisey piece of junk. The short cycle is from low pressure in the system. I would check the hoses and compressor connections with leak check(soapy water) to find a leak before adding more R134. I just had the same thing on my '86 and it was a leaking from the high pressure schrader valve and a bad hose on the back of the compressor. The fan comes on at around 219F on mine when the a/c is on or not.You might have a bad fan motor, relay or sensor. I would attack the problem first that is effecting your driving the most. good luck.

 

First of all, make sure that is a new compressor, not a rebuilt one. You cannot successfully rebuild a R4 compressor. New ones, (A/C Delco), if installed right and have the proper amount of oil (PAG 150), new accumulator, flush the system well and a new orifice tube and it should service you well. I've installed 100's of them over the years here in hot SE Texas. If the compressor is cycling, chances are you are either low on freon or the low side pressure is going to low due to a restriction in the high side. Need to check pressures with a gauge.

 

I agree 100% with mech259.