Compressor venting Coolant...

[moret]

The quick and dirty is that a valve on the rear of the A/C compressor is sputtering every time the system is engaged. Below are more details. Thanks in advance for any insight you can provide...

Background:
I have a '93 XLT, which has been professionally converted to R-134. For the past 3 years, each summer I've recharged the system with a pound of coolant myself. This year, after recharging the system, the air was warm in about 2 months. So, I took it in and asked them to find the leak. They said there was no leak (much like the last time I asked a shop to find it) and recharged it.

The problem:
Two days after they recharged the system, a valve on the rear of the compressor (anyone know what this valve is called?) started to exhaust the coolant. I shut off the AC, and subsequently the engine. The coolant continued to exhaust until the system was empty.

I took it back to the shop, they replaced the valve, evacuated, and recharged. After running for 10 seconds, the new valve started to sputter. Once the AC was turned off, it stopped. They said it was the compressor. They've replaced the compressor, evacuated, and recharged. Before it was out of the garage, they started the AC. Again, within 10 seconds, the valve started sputtering coolant, and would stop once the clutch was disengaged.

The questions:
What is this valve on the back of the compressor called?
What would cause it to sputter?
If the coolant was contaminated, either in the shop's tank or due to a malfuntion in the shop's equipment, could this be the cause?

Sorry for being long-winded, and thanks again,
-Moret

 

[shamaal]

It's the high pressure relief valve. Shown on right in picture. If it is indded the valve opening, a couple possibilities come to mind:

1. Bad valve
2. Blockage in system

Sometimes there is damage to the grooves for the o'rings in the connector block that goes to the back of the compressor that gives the appearance of the valve opening. I would think there would be a very high indication on the high pressure gauge that the A/C techs would see.

If the coolant was contaminated with particulate matter sufficient to cause significant blockage that could be a possibility.