1963 Riviera Suction Throttle Valve

[Guest oakland]

Does anyone know where I can find a suction throtle valve for my 63 Riviera? I am trying to get the air condition working, and the mechanic said that the suction throtle valve is bad. I would appreciate any information. Thank you.

[Mr Riviera]

Try Old Air Products in Texas. If not I may have a kit to rebuild it.

[NTX5467]

The "reason" it's "bad" might determine how to deal with it. If it's a cooling issue or related "icing" issue, it would mean a possible calibration issue rather than "not working" type of "bad". Is the mechanic using R-12, a hybrid replacement, or R-134a?

In the old www.aircondition.com website (which I believe has a redirect now), it mentioned that with POA valves, sometimes they'd stick and a shot of air pressure might free them up and then they'd work as designed. Not sure if that might work with your STV, but that or several "taps" on the valve might unstick it internally. Doing a rebuild kit could also mean the need for some special tools or expertise in executing the rebuild.

In that same website, along about 2003, there were some posts about POA valves being adjustable (internally), plus the sticking issue. Those posts also referenced other posts for other cars that told how to adjust the POA valves to lower the low side pressure to 26psi from the R-12 spec 29.5psi. Something like less than 1/2 turn of the adjustment screw to get the lower pressure, which resulted in the low side and high side pressures having basically the same differential relationship with R-134a as with R-12, AND similar 40 degree vent outlet temperatures. Other than the adjustment, all it took was replacing the existing R-12 oil with R-134a compatible refrigerant oil and possibly hoses with a new dessicant mechanism being recommended. The posts also mentioned that the same adjustability was also present on the earlier hot gas bypass valves that GM used prior to the STV configuration. Plus on the later CCOT system which had an adjustment screw on the cycling switch.

Knowing why it's bad might help in determining how to proceed.

Just some thoughts,

NTX5467

[Guest oakland]

The reason I say the suction throttle valve is bad on my 63 Riviera, is that I had the car in to get the air conditioning working. When the mechanic went to flush the old R-12 out and install the the new coolent, the valve leaked fluid around a seam where it bolted together. He tried to seal it but could not. He said that he thought the diaphram was blown in the valve.

[NTX5467]

Thanks for the additional information.

NTX5467

[BamaWildcat]

See this link for an exploded view, what it does, who sells kits, and who rebuilds them.

http://www.1964buick.com/resto_logs/stv.htm

A rebuild kit is not that hard to put in and it beats buying a used one for serious coin.

Note the Riv STV is a little different, but all my links still apply.

[Guest oakland]

Thanks for the info, Bamawildcat. I checked out Ebay and found a new rebuild kit, after you mentioned that you found one there. I purchased it for $29.95 including shipping. No "O" rings though. Will have to find them somewhere else. The info will sure come in handy.