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New compressor. Not cooling well.

Posted: Sat Jun 02, 2018 4:53 pm
by Dgreen
Compressor was making bad noises. My buddy cut the belt. AC was short cycling when the noise started. Still made noise with AC turned off. System was empty this morning when he brought it over. Took the orfice tube out and it was clean so we proceeded with replacing the compressor, orfice tube, accumulator, and belt. Vacuumed and charged with 28 oz of refrigerant. Vent tem was in the high 60s. Disconnected gauges and the high side service port was leaking bad. Recovered the charge and replaced the service port on the high side and the Valve core in the low side. Vacuumed and charged it again. Vent temp 75 to 80 at idle. Got down to 57 on the highway.

At idle
Low side 62
High side 195
Vent temp 75

1500 rpm
Low side 56
High side 325
Vent temp was going down, but not like it should.

Fan will hold a rag on the grill at idle. Sprayed water on the condenser and vent temp was still in the high 70s at idle.

Is the new compressor the culprit?

Re: New compressor. Not cooling well.

Posted: Sat Jun 02, 2018 4:56 pm
by Dgreen
I forgot to add, it was 84 degrees outside and really humid.

Re: New compressor. Not cooling well.

Posted: Sat Jun 02, 2018 6:19 pm
by Cusser
What vehicle, what model, what year?

Didn't "buddy" know how to remove an AC belt?

Your low side pressures are quite high.

Re: New compressor. Not cooling well.

Posted: Sat Jun 02, 2018 6:44 pm
by Dgreen
It's a 2004 GMC 1/2 ton with a 5.3.

Re: New compressor. Not cooling well.

Posted: Sat Jun 02, 2018 7:53 pm
by 71403
Verify recirc door is closing and temp door actuators are working to full "cold" position.

Re: New compressor. Not cooling well.

Posted: Sat Jun 02, 2018 8:05 pm
by Dgreen
Clamped off the heater hoses. Didn't change anything.

Re: New compressor. Not cooling well.

Posted: Sat Jun 02, 2018 8:20 pm
by Tim
Pressure readings?

Re: New compressor. Not cooling well.

Posted: Sun Jun 03, 2018 4:20 am
by Dgreen
Pressure readings are in the first post.

Re: New compressor. Not cooling well.

Posted: Sun Jun 03, 2018 6:31 am
by Mr Bill
Dgreen wrote: At idle
Low side 62
High side 195
Vent temp 75

1500 rpm
Low side 56
High side 325
Vent temp was going down, but not like it should.

Fan will hold a rag on the grill at idle. Sprayed water on the condenser and vent temp was still in the high 70s at idle.

Is the new compressor the culprit?
Looking from cyberspace, those pressures at idle seem high, especially the suction, if you spray water on the condenser at 1500 rpm, does the high side pressure drop any/much?

Re: New compressor. Not cooling well.

Posted: Sun Jun 03, 2018 6:39 am
by Dgreen
I didn't have the gauges on when I sprayed the condenser, but the vent temp was in the 70s after I hosed it down.