GM A/C INFO

[beebow]

Just an FYI for everyone. I've been having some A/C problems on my 95' Sierra. I found that the R134 was low and put a can in which allowed the low refrigerant switch to activate. The funny thing is there were no leaks. I know a guy that is a GM tech and he gave me some info about A/C hoses. Over time GM hoses degrade and become permeable. This allows refrigerant to leak "very" slowly so it's hard to diagnose. You can get a few more years out of them by refilling the refrigerant, and then look at replacing them. Anyone heard of this before?

[mbb1]

I have a 95 k1500

 

All my freon leaked out. The high side fitting on the compressor discharge leaks on mine. I have been relying on a VERY tight strong cap to minimize the leak here for a year. Did not run truck in several months, went to recharge AC because wouldnt come on (jump low pres switch with paper clip). compressor make light squeal sound. Leave freon can going in and go in house to get warm water , come out and compressor is SMOKING. Oh $hit, compressor has crapped out.

[citydriver]

Over time GM hoses degrade and become permeable. This allows refrigerant to leak "very" slowly so it's hard to diagnose. You can get a few more years out of them by refilling the refrigerant, and then look at replacing them. Anyone heard of this before?

 

Yep,my '95 does the same thing

 

BUT you gotta be carefull NOT to OVERCHARGE the system.....

[OUMike]

Man...everyone havin' AC trouble. I'm startin' to get so with my AC. Works sometimes, then doesn't. I'm startin' to think maybe low pressure switch (that was dealer replaced about 6 mon ago) has gone south. If the low pressure switch was dead would that effect the pressures of the compressor? My pressure is low, but won't take anymore freon. System doesn't need a charge, but is running low. Compressor or Switch??

[citydriver]

If the low pressure switch was dead would that effect the pressures of the compressor?

 

 

Yes,in a way it would...the compressor will not turn on if the switch is OPEN indicating LOW PRESSURE...the system is designed that way to help prevent compressor damage.......If the switch has an intermittent fault it would cause the comp. to kick in and out...HOWEVER low refrigerant will cause the same thing..

SO there is a fine line,the only accurate way to check the level is to do a complete evacuation and refill of the system which costs $$$,the average do it yourselfer doesnt have that kind of equipment layin around(I know I dont)....just be aware that it is the refrigerant that carries the compressor oil to lubricate the system,no refrigerant = no oil to the compressor....so if you jump the switch to check comp. operation..DO NOT RUN IT THAT WAY 4 LONG(10-15sec.MAX) just long enuf to check the pressures w/gauges ...compressors r NOT CHEAP