Automotive Air Conditioning Information Forum

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?

I forgot to add, it was 84 degrees outside and really humid.

What vehicle, what model, what year?

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

Your low side pressures are quite high.

It's a 2004 GMC 1/2 ton with a 5.3.

Verify recirc door is closing and temp door actuators are working to full "cold" position.

Clamped off the heater hoses. Didn't change anything.

Pressure readings?

Pressure readings are in the first post.

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?

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.