high side maxes out gauge and freon leaking past compressor seal at startup

[drhill]

UPDATE: Now my AC works fine. When it spiked the high side, It acted like the compressor got a glug of oil and was tryin got pass it through. I've had this happen to me before when I over oiled another system but this one was flushed, vacuumed and oil carefully measured. plus it's been working fine for a year. Any thoughts?


Hi Everyone, I was on this board years ago but I had to start a new account because I've been inactive for a long time.

1984 Mercury Colony Park Wagon
Sanden 508 compressor (engine swap so used this compressor and custom lines made)
OEM style orifice tube
aftermarket parallel flow condenser
charged with R12 to slightly less weight than oem due to shorter hoses
high side: 500psi plus
low side 65-70 psi

Everything has been working fine for the year or so that this system has been in place. All of a sudden today I noticed a puff of white smoke from under the hood and saw freon and oil escaping from the rear seal on the compressor. Put my gauges on and started the compressor again and the high side immediately shot to 500 psi(max on my gauge) and low side was about 65 to 70 psi. Static pressures before this were about 145 psi (114 ambient today outside). Also, the last time I tested the system the high side stuck at 375psi and is still there 15 minutes later.

Any thoughts? Assuming a clog somewhere (condenser, orifice tube) but low side did not drop too much when turned on. Weird that this happened out of the blue with all new parts a year after install...

[JohnHere]

With pressures like that and with the HP safety valve venting, my first thought is that it's overcharged. Did anyone add any refrigerant lately?

Also, use extreme care when working on this system. A burst hose or other component is a distinct possibility with such high pressures.