edwinsmith

In prep for my vacation starting in the morning. I decided to top off the A/C on my trouble prone system. The stupid pop-off went again and spewed oil all over the compressor and the belt. I first thought it was because of the fans fuse blowing under heat so I relocated it away from the condenser. But the high side pressure still gets up to almost 600 psi and then the pop-off goes again.

A while back I noticed that Jim Lane's condenser is much larger than mine. Jim, do you have a part number for yours? Did your system come out with R-134A from the factory? Also what is the p/n of your expansion valve?

Regards

Edwin

Angry Johnny

600 PSI is not because your condenser is too small. Something is clogged up and it's probably debris in the condenser from a failed compressor.

This is what I did on mine and you have to do it all at one time. New compressor, H valve, drier, evaporator and aftermarket condenser designed for R134a. Flush all the lines and hoses, ideally you would want to replace them with barrier hoses but I didn't and it still works just fine after 2 years. I also mounted two 8 inch fans in front of the condenser, wired to relays that turn on when ever the compressor clutch kicks on. This will help it cool at low speeds and keep the head pressure down.

edwinsmith

I have replaced everything except the evaporator. I flushed that out very well and it is not clogged. I need the aftermarket condenser made for R-134a which is what's causing my problem. I just need a source, P/n etc... I also have the fans.

Edwin

1972RedNeck

While a parallel flow condenser will make it work much better, you have something majorly wrong if your pressures are getting to 600 PSI.

Jim Lane

Edwin,
Here some pictures of the parallel flow condenser that I installed on my truck.
I had O'reillys order it for me.











Here is the expansion valve that I used.





I converted my truck to use a Sanden SD-708 compressor,
I welded aeroquip fittings onto my old lines, now I can easly replace a hose if it ever goes bad.



I had to dig through about 8000 pictures to find them.

Before I installed it, I used a large adjustable wrench (Crescent wrench) and had to straighten the ports so they would fit the opening in the core support.

Agreed, 600 PSI is way too high, too small of a condenser or not enough airflow could cause that, is it possible you are overcharged? are you using R-12 or R-134a?

Have you replaced the lines?

I had my discharge hose delaminate and fill my old condenser with the bits of the hose.

If you need to see any pictures, it would be easier to send you the files on CD than for me to host them.
Jim

1972RedNeck

Could we get this "stuck" in the sticky for future reference?

edwinsmith

Thanks Jim for the Pics and the P/N. I'll have to check mine but that looks very similar to what I got for mine. I seem to remember a pic of somebodies that had the condenser that extended up on both sides of the hood latch assy. It looked bigger. I thought it was yours. I'll go look through the threads and see what I can find.

I've been busy here in KS with visiting people, swapping transmissions and messing with clutch cylinder problems. Today we went out to the airport and scattered my brother's ashes in the grass by the runway. He loved flying before he died and those were his wishes.

Edwin

bigragu

Sorry to hear about your loss, Edwin. All this time I thought you were prepping for a vaca. Rest assured you made your brother happy, by respecting his wishes.

Jim Lane

Hey Edwin,
Sorry about your loss,
The size of the condenser is decieving, the transmission cooler sits along the top under the hood latch if you have an automatic transmission.

I lost my only brother about 8 years ago at the hands of drunk stoned driver, he t-boned his car at about 60-mph and then lost my dad a year ago.
Jim

bigragu

Man, Jim, that's terrible.

Angry Johnny

Sorry about your brother.

Back on topic. You have a blockage somewhere. Operating the system at that kind of pressure will damage the compressor as well. That is an extreme amount of heat. Trust me, not only am I a 42 year Mopar tech I also went through this with my truck. I tried several times replacing components piece meal. The partially plugged condenser took out my new replacement compressor. I'm sure it had debris in it from the original bad compressor. You can't really flush those things out well. It's best not to fool around and just do it all at once again. I went through two compressors, 3 driers, and 3 h valves before I stopped wasting money.

I got my condenser from Rock Auto.

1972RedNeck

This is good advice.

MrFusion

I overcharged my jeep Cherokee A/C once. I fried the clutch on it (literally smoking) within 5 miles because it was working against excessive head pressure. A/C now disconnected but I'll replace everything this summer.

kevin93

Go googling for a R-134a temperature pressure chart...345 is the highest when it's 110 degrees F out...600 psi means something is clogged. On the "high side" of the pump, that would have to be the receiver/dryer or the expansion valve.

*Maybe* it's possible that the condenser is clogged with debris of some sort....but since it's a bunch of tubes it would have to be a lot of accumulation of stuff, that would have first gone through the condenser...this is unlikely.

BC847

So, what was the low (suction) pressure while the 500 ~ 600psig high (head) pressure was going on?