I removed the high pressure side plastic cap at the compressor and refrigerant came out under pressure. Is there supposed to be a check valve to prevent this?
There should be a valve, similar to the valve in your tires, to prevent refrigerant from escaping but allow refrigerant to be added. Perhaps the valve is faulty. The plastic cap is just to protect the valve, not to contain the pressure.
Why did you remove the cap?
The system is cooling but not with temp drop you would expect… I was looking at the compressor to see if I could deside which as the high and low side service connections.
If the valve is leaking refrigerant is escaping. This would explain the lack of proper cooling. Take it to an AC shop and let them install a new valve and the correct amount of refrigerant.
Am I wrong? This is very very dangerous to be messing around with the high side. Everything is done from the low side. People have lost eyes etc. from this. Take it to a shop.
The warning about the high side is dont open the valve on your gagues if you have a can of refridgerant tapped on the delivery hose (engine running). It is standard to hook up to the high side,you want to know the pressure,some guys evacuate with both sides open (presssure is not a problem then).
I get it. Since I have no desire to vent the remaining refrigerant to the atmosphere, I will take the Tahoe to an authorized service center, for replacement of the shraeder valve and a recharge. Thanks