Compressor Oring

[dburkett8]

Hello

I am restoring my AC system and the oval fittings that connect to the compressor seem to require an o RIng to fit in an indented space. Can any r134 o ring work or does it need to be a special one?

Thanks

Dane

 

[idrivemopar]

you are talking about the high pressure and low pressure fittings on the compressor. Yes, 134 o ring should work, but you also need gaskets for both of those connections and by the way the gaskets are not identical, notice the difference in the picture. Also don't forget the epr valve should be removed and a secondary temp switch should be installed on the evaporator side of the compressor.

 

[dburkett8]

you are talking about the high pressure and low pressure fittings on the compressor. Yes, 134 o ring should work, but you also need gaskets for both of those connections and by the way the gaskets are not identical, notice the difference in the picture. Also don't forget the epr valve should be removed and a secondary temp switch should be installed on the evaporator side of the compressor.
View attachment 418511

Thamks!
Another question- so secondary temp switch will take the place of the epr valve?
By chance do you have a picture of the epr valve so I can verify what should be removed. And when purchasing the secondary temp switch are their any specific characteristics I should be looking for?

THanks
Dane

 

[idrivemopar]

The removal of the EPR valve from the compressor was recommended by the place that rebuilt my compressor and recommended for 134 conversion because it can freeze up. EPR Valve is on the side toward the firewall, or what's called the suction or low pressure side of the compressor. If you take of the fitting on that side, you will see a screen inside the fitting, followed by a spring, then the epr valve inside the compressor.

For a thermostatic switch I and a few other people have used the Murray part#35720, it goes off at 30.5 degrees, which you want a bit below freezing because the capillary for it will need to be placed on the evaporator pipe just coming out of the firewall and electrically, it will be placed inline with the compressor positive connection.

 

[dburkett8]

The removal of the EPR valve from the compressor was recommended by the place that rebuilt my compressor and recommended for 134 conversion because it can freeze up. EPR Valve is on the side toward the firewall, or what's called the suction or low pressure side of the compressor. If you take of the fitting on that side, you will see a screen inside the fitting, followed by a spring, then the epr valve inside the compressor.

For a thermostatic switch I and a few other people have used the Murray part#35720, it goes off at 30.5 degrees, which you want a bit below freezing because the capillary for it will need to be placed on the evaporator pipe just coming out of the firewall and electrically, it will be placed inline with the compressor positive connection.

Thanks!!

1 more question , does it matter where the secondary switch is placed on the evaporator to compressor line? Close to compressor or evaporator?

 

[RJS]

The side with the large "O" ring doesn't require and gasket. Look in your service manual only "O" ring pictured.
Ron

 

[idrivemopar]

73 SM show gaskets on both sides!

 

[RJS]

I don't speak 1973 I was referring to my 1972 which only uses O-ring per the FSM. I don't believe the OP said what year he was working on though now that I think about it.
Ron