a/c questions

[93stang burden]

I finally decided to put some a/c back in my system that worked last yr. well i put a new motor in this spring and had to realease it all. well now i put 3 cans about 30 oz of 134a in the car and a 3 oz can of oil on the low side right on top of th compresser. well after about 3 or 4 minutes the stupid thing kinda does a blow off valve and lets the pressure off and then continues. Did i put in too much or what?? any input would be aprreciated.

 

[jrichker]

Did you vacuum the system down good before adding the refrigerant? You need to pull a minimum of 28" vacuum for 30 minutes before adding refrigerant.

 

[93stang burden]

yep pulled a good vaccum with my pump. but right beside the spot where you fill it on the low side on top of the compressor there is a like blow off valve and its like once it builds up pressure it jsut does a short discharge then another. is there any way to test the switch on the canister??

 

[jrichker]

The switch on the canister is the low pressure cut off. It is supposed to turn the compressor off when there isn't enough refrigerant to properly circulate the oil.

R134 Refrigerant charge is 26-28 Oz plus 6-8 Oz of PAG 100 oil.

 

[93stang burden]

ok i put that much stuff in but why would do this crazy blow thing??

 

[liljoe07]

Its possible you have a blockage in the orfice tube, causes the real high pressure on the high side, and low suction pressure. Not even sure if auto ac systems are supposed to go into internal relief( or external in your case).

 

[93GtMustang50]

did you convert your system to r134a? Maybe thats the problem. Adding r134a to a system designed for r12 will cause all sorts of issues.

 

[Lawbreaker5.0]

Three cans is too much. And that valve is a release valve. When you have too much pressure on the high side it will blow out of it. I just did mine two days ago and only needed 2 cans. 14oz cans x 2= 28oz.