735 cat rock truck B1N00203. Had some a/c issues. Hooked gauges up both static pressures are correct according to outside temperature. Around 85psi. Start the machine engage compressor low side drops into about -10inhg high side goes about 100psi. Thought had a orfice valve problem. Changed orfice tube and drier assembly. Also changed accumulator. Flushed evaporator seems fine. Charged system and pressures still the same. The drier outlet and evaporator inlet gets super frosty. Any A/c experts on here. I would think if the condenser was plugged my high side pressure would be very high.
The only other thing I can think of is the line going from the accumulator back to the compressor is pooched or Is it possible my scales are off and the charge is low? Let me know your thoughts.
If the gauges equalize quickly to the static pressure after shutdown, there could be a broken valve in the back of the compressor. If the valves are good, it takes a few minutes for the pressures to become the same. Do you have any way of checking your scales, because it could be low charge? Otherwise, maybe the suction hose is kinked under the cab or at the back of the engine.
Recovered this morning with new scales got 2.2lbs out of 4.5. Vac and recharged all good.