Eastflorida

It appears to have factory air but it is barely cool. Seems to be converted to 134a. Had a local guy add some Freon, but he was afraid to add too much.

Anyway, can the factory setup be made to work OK or do I need to do something different?

The "best" a/c guy in town is out for a few weeks. I'm told he's an all or nothing type... I just want my "weekend driver" to be cool in the FL heat. I don't expect it to perform as my newer truck does.

I've seen pics of other cars with what appears to be factory but with a different compressor?

Thoughts/suggestions?

Thanks!

Fun71

Looks like an original compressor but with a pressure cycling switch installed in the low pressure line. This would make the system cycle on/off during operation, so you can check to see if it's cycling rapidly (low on refrigerant), or not at all (overcharged). If it's cycling, measuring how long the compressor is engaged and disengaged helps with troubelshooting, also.


He was afraid to add too much? Was he using a gauge set or just a charging hose? If he had gauges, he should have been able to get the proper amount of refrigerant added.

Eastflorida

Fun71,

It originally was cycling every few seconds (rapidly). After adding the Freon, it seemed to cycle normally. He had it hooked up and was concerned about the high side pressure????? He added dye and didn't see any leaks... I'm just curious what I should expect from my setup if "properly" configured will meet my expectations...

Do I need to time the cycle frequency to help?

What "other" compressor do I see in some photos?

Thanks for your input, I'm an A/C idiot...

redoldsman

They system worked well when it was new so you should be able to make it work again. The compressor you are referring to is probably the Sanden compressor which is very popular. I have one on my 54 Olds. I imagine there is a kit to adapt it to your 72. It is a big improvement over the A6 compressor that came on your car.

joe_padavano

The real problem is that the A6 compressor is not designed to be a cycling style compressor. That's why GM used it with an POA valve - think of it as analog vs. digital control. If you plan to keep the POA valve eliminator, change your compressor to a modern one. You can get brackets for the Sanden, or get something like the Pro6Ten compressor that fits the stock A6 brackets (but weighs less than half as much!).

Fun71

I was told during my research years ago that is the big issue with R134A conversions in hot environments. The high side pressure can get so high that the front seal can blow out, so in hot climates an auxiliary electric fan is recommended to help remove heat and keep the pressure within reasonable limits. This is the main reason why I did not convert the AC in my car to R134A as Arizona definitely qualifies as a hot environment.

So you said it is barely cool in your first post.
Is this while idling or while cruising? R12 is much more efficient than R134A conversions, and they will not cool as well at idle but should be OK while driving.

Do you know what the vent temperature is? At idle and while cruising?