Engine Size: 7.3
Refrigerant Type: 134A
Ambient Temp: 93
Pressure Low: 46
Pressure High: 175-225
Country of Origin: United States
System is not cooling well. Here is the info that I have. It was recorded on two different times.
The truck is a 2000 Ford Excursion 7.3 diesel with rear air.
System was taking to long to cool off, so I hooked the gauges to see what was going on.
Suction side was 70 psi. high side was ~225.
I thought the charge was high so I used and empty 30# can and ice to recover some charge. I go the pressures to
Suction 46 psi
high side was jumping around 175-225
Duct discharge temp after 20 minutes of driving (90 degree day) was 58-60
I drove it but it still is not cooling well.
temper measured with IR gun
Evap box rear air lines
85 degrees at expansion valve 76 after txv
74 degrees leaving the coil
160 degree discharge
110 degree suction
Front expansion valve
Looks to be undercharged, with some other issues.
Recover the charge, and pull the orifice tube for the front system. It should be a Red tube. If it is not badly contaminated, you can probably get by with a couple of ounces of oil, and some dye for testing.
Get the full charge into the system by weight. Diagnosis is not possible without a full charge. Running it undercharged starves the compressor for oil.
Run the fully charged system with both evaporator fans on the highest speed, and the front doors open. Run the engine @ 1500 rpm for 5 minutes, and record the high & low pressures while holding 1500 engine rpm. Post the results.
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.
What do you expect the suction line pressure to be?
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