OEM A/C compressor condition/aftermarket replacement recommendation needed

NIGHTHAWK4570

MEMBER
2001 FORD RANGER
3.0L
V6
2WD
AUTOMATIC
240,000 MILES

I'm preparing to overhaul the air conditioning system on the truck listed above. Parts being replaced are the condenser, accumulator, orifice tube, evaporator core, cycling switch, pressure cut-off switch, suction/discharge manifold hose assembly, and the condenser to evaporator line.
The only part I'm undecided on whether to replace or not is the compressor which is the OEM. The clutch still functions, but I'm concerned about the overall internal condition of the compressor considering its age and the pressure relief valve having blown at some point.
When the system was last charged, it worked properly blowing cold air for about 20 minutes with both low and high pressures in range on the manifold gauge set. As the system continued to run, something blew dumping an excessive amount of condensation onto the floor beneath the area of the evaporator core and accumulator. Condensation also appeared on the inside surface of the windshield. Oddly though, the following day, the system held vacuum again. Later on, I leak tested with UV dye and discovered that the pressure relief valve was blown. Following all of this, the system was evacuated, vacuumed, and has remained empty for the past year or two now.
Considering the age of this OEM compressor and the pressure relief valve having blown, despite that the clutch still functions, would replacing it be recommended even if the replacement compressor would have to be an aftermarket brand due to cost?

3 Replies

STEVE W.

MECHANIC
13,414 POSTS

I would replace it. From your description it sounds like there was moisture in the system that froze and caused a pressure spike that caused the high-pressure valve to open. I wouldn't trust a compressor that had seen a spike like that, especially as you are replacing the other parts that you would replace in the event of a compressor internal failure. It wouldn't be fun to get the system complete and have the old compressor fail and now you replace the orifice tube and accumulator again to remove any shrapnel from the failure. I would suggest the optional extreme climate orifice tube, if possible, it allows for more cooling than the "normal" tube and gives better results in hot weather.
As for removing the factory compressor you remove the air cleaner housing and duct, then the line block from the compressor. Next remove the belt and unbolt the compressor.
On install torque the mounting bolts to 18 ft lb. (careful as you can shift the seal in the compressor if it doesn't set flat on the mount prior to tightening the bolts)
Be sure to dump the new unit and measure the oil, as you are also replacing the core and accumulator and most of the lines as well you will want to add additional oil to the system. Total capacity is 9 ounces of PAG oil. For that you want to pour five ounces into the compressor, then spread the rest between the cores and accumulator. Then I recommend a two-stage leak test, first charge the system with CO2 or Nitrogen Then use soapy water or a CO detector to check all fittings and parts. No leaks there? Pull a vacuum and verify it holds, if it does charge it up with 30 oz of R134A and test it out. Ideally you want to see about a 30-40 degrees difference in ambient vs center vent temperature.

https://www.2carpros.com/articles/replace-air-conditioner-compressor