2000 isuzu rodeo a/c

Hi All, I have a 2000 4x4 Isuzu Rodeo with 3.2 liter engine. This car has started to not cool well, especially while stopped. I bought it in 2004 with 19,000 miles, so I doubt it has ever had it"s a/c system opened. I hooked up gauges expecting to find it possibly needing a charge and saw that the low side was running high (70-90psi), and the high side was low(130-200psi). From looking at the repair manual, it looked like the problem could be the expansion valve. I replaced the expansion valve and the receiver drier, vacuumed the system for an hour and recharged with the proper amount of refrigerant (23 oz). The pressures are still the same as before. The tubes going to the evap are pretty much the same temp, and I have 78 degree air from the vents. The new receiver drier came with the clear port for observation of system - it has a lot of frothy bubbles flowing through it. I do not know if this is a big deal or not, But I charged the system by weight, rather than filling the system till this port cleared up.

Now, since I have replaced the only thing I can think of that could cause these pressures other than the compressor, Do you think it"s time for a new compressor?

Sorry for the long post, hopefully not too rambling.........
Thanks in advance,

Rob

Have you looked at the condenser in front of the radiator? Does it have alot of debris,bugs or bent fins? Needs LOTS of airflow to keep pressures down.

If all is good there,the compressor may be next in line.You should see virtually no bubbles in the sight glass at proper charge.

Hi Brad,

Yes, condenser is clean with no bent fins. Ordered a compressor yesterday - $370.00 - ouch!
I believe it will take care of the problem....

I think there must be an internal leakage between the high and low sides in the compressor, causing the bubbles in the glass.

Thanks,

Rob