I'm not an AC professional, but know "some". 1. I've used that aerosol can flush to backwards flush the lines on my own vehicles. 2. Always use brand new green refrigeration-compatible O-rings when assembling. 3. I add the oil to the compressor, then rotate with a socket at least 10 revolu...

I don't have my 1988 or 1994 Suburbans any longer that had R4 compressors, but I'm not positive that these systems were made to cycle; like maybe running full time and one would just blend in some heat if the vent temperatures were too cold. If you're in a humid-enough climate, wouldn't you notice e...

AI9 - you mentioned that this type of compressor is sensitive to pressure, do my pressures at idle and rpm look ok. I'm wondering if they're a bit high. Outside temp ~85degF, engine at idle, Low 40 psi and High 250 psi, Interior fan running at 1/2 speed, vent temp 45degF Engine at 2500 rpm, Low 30 ...

Bill - if your comfort is OK, then everything is OK.

jerryjerry05 wrote:I try to jumper power to the fan/clutch, nope. The lead gets smokin hot?
I try to bypass the high pressure switch, nope. The lead gets smokin hot?

If you did those tests as I think you did, might be a grounding in the AC clutch.

Hmmm - sounds like TOO MUCH refrigerant from your pressures??? I have no experience with that refrigerant; RedTek is R12a. This link states that it will require only about 35% of the same charge as R12 to get the same (or most likely better) results. https://www.allpar.com/forums/threads/messing-aro...

The fans respond well enough to the dashboard control (significant increase in fan noise with each increase) but not much air seems to be blowing through the vents, certainly not as much as I would expect. Well, with small air flow out the vents, either the air flow is being diverted to the windshi...

I've flushed new compressor myself. About 15 years ago I bought a compressor from the board sponsor, for my '88 Mazda truck. It arrived with oil, but a PAG oil (I could determine that readily from a drop of oil in 5 minutes using the infrared spectrophotometer). Since I was still using R-12, I had t...

Dougflas wrote:You can only flush the compressor by filling and dumping the oil a few times.

And turning the compressor through like 10 revolutions by hand or with a wrench, then dump.

Good that you did not "use a kit", some can damage a system permanently. Ask your friends/look online for an independent ASE repair shop (ASE certified) that they like. For you, start up the engine with AC off, and look at the AC compressor; you should see the outer pulley turning but the ...