Mechanics

AC BUILDS UP PRESSURE ON THE LOW SIDE.

2002 Oldsmobile Bravada • 130,000 miles

My ac builds up pressure to about 100 psi on the low side, which causes the compressor to kick off. If its cold out the compressor will run for a little bit, but if its warm out the compressor will not even kick on.
I've already changed the and ofifice tube and tested the low pressure switch. What do I do?
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Samd74
June 24, 2012.




Sounds like it is way overcharged. Did you evacuate the system and install the exact amount of needed freon?

Roy
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ASEMaster6371
Jun 24, 2012.
We did just evacuate the system and refill it last night. It was running fine and than it spiked and the compressor kicked off. We had this problem before that why we had to change some parts. The only difference was that in the morning the pressure would drop and the compressor would run for about ten minutes and than the pressure would spike again? Would the high pressure sensor be going bad?

Tiny
Samd74
Jun 24, 2012.
No, what parts? How much freon did you install?

Roy

ASEMaster6371
Jun 24, 2012.
We installed a accumulator and orfice tube. My dad put the freon in. He might have to much in. It ran fine right after he put the freon in and than it started acting up like it was doing before. It would run than the pressure would spike until it would cool down and it would run again at a pressure of 40. The only difference is the pressure has stayed the same now at 100.

Tiny
Samd74
Jun 24, 2012.
High or low side. The high side should be 2 times the outside air plus 15%. The low side should be around 25-35 lbs.

If not, then there may be a restriction in the system.

Roy

ASEMaster6371
Jun 24, 2012.
It's the low side that keeps reading high. Where might the restriction be and can I do a test to narrow my search? Could it be something electrical tripping the compressor?

Tiny
Samd74
Jun 25, 2012.
What is the exact high side pressure?

Roy

ASEMaster6371
Jun 25, 2012.
Not sure what the high side is I don't have the gauge with me now. The last time I did a reading the high side was 60 but not sure exactly.

Tiny
Samd74
Jun 25, 2012.
The high pressure should be higher than that-150-220 psi could be still low in freon or compressor problem

Rasmataz
Jun 25, 2012.
I dont have the gauges with me. I tried adding freon, but I cant even get the compressor to kick on any more. You need the compressor running to get a proper reading right? Is there a way yo get the compressor to kick on by bypassing anything? Ive already tried bridging the low pressure switch. I dont know how to bridge the high pressure because it has 3 wires.

Tiny
Samd74
Jun 25, 2012.

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