Pinhead

I know there are quite a few threads about A/C systems not working, and mine is no different. However, mine has a little different problem than I've heard. When I turn the A/C on, the clutch engages but makes a helluva loud noise and a green substance (freon?) shoots out of what looks like some type of overload or overflow valve. There's no hoses going to it, and it looks like it was made that way (not broke off). I can tell it's green because it left a thick green film on my motor mount and frame directly below it.

The clutch engages for a second or so and then disengages for a few seconds, only to kick back in and spew this junk out. I don't know a whole lot about the technicalities on an auto A/C unit, but I know where the condenser (front of radiator), the evaporator (in the cab), and the pump all are, but what controlls what and where is beyond me. I'm extremely technical minded so I'm sure I could figure it with the right guidance. I'd rather not fork out $500 to have someone work on it, so hopefully with the forum's help I can get this figured out. Thanks!

Johnny Mullet

That green fluid is actually Freon with A/C leak dye in it. I would hook a set of gauges to it and see how much pressure the high side reads when it spews out.
Maybe it is over-charged or maybe the compressor is failing.

Pinhead

I think it was overcharged, since the PO charged it himself 'cause he thought it wasn't working. In fact, the AC works, but the vacuum controlled heater core thingy (bypasses the water to the heater core) isn't working. There is no vacuum at the unit. The heater was constantly on, so it always blows hot air. However, if I put it on Max AC the air doesn't blow over the heater core, and it blows nice cold air.

That brings me to two other questions.

1) How do I test the pressure in the AC?

2) How do I go about figuring out why there is no vacuum to shut off the heater core? I just put in a new bypass valve and I know it works. It depressurizes when I turn the engine off, and the valve works. What to do?