Latest 55 A/C Adventure.

[Paul Falabella]

This past winter I sent the hot gas bypass valve(which catastrophically failed last year), the expansion valve and the receiver drier to Old Air for service. When I first put them in and charged the system(R12) the duct temp was close to 60F. Remembering that Willie once said the hot gas bypass valve was  possible trouble ,I disconnected the power. The duct temp went down to 50F. I next opened the the expansion valve and found it was wide opened. I played with the adjustment and found that approx. 3 1/2 turns from closed produced a duct temp of 39F. So far so good!

Edited June 7, 2015 by Paul Falabella (see edit history)

[old-tank]

Good deal Paul. I'll send you some hot weather to give it a workout.

Willie

[JamesBulldogMiller55Buick]

Cool !!

[Paul Falabella]

Checked the power to the hot gas bypass valve today and found the voltage to be 11.3 no matter where the temp control was placed. So I will assume there is something wrong with the temp rheostat. The 1954 Cadillac A/C manual says to check the valve by applying battery voltage which I did. If it is working an audible click can be heard, which it did. Not that it matters that much.

 Yes Willie and James, since Al Gore invented the internet and global warming,the NYC area goes from cool damp springs to hot dang summers overnight!

[old-tank]

The hot gas bypass valve (actually a liquid bypass valve) is generally useless on 55's.  Even when working correctly, it regulates temp before you want it to.  Around here I leave it disconnected to achieve 'max a/c' at all times...if it gets too cold or the evaporator freezes,  just turn off the compressor by moving the temp control all the way counter clockwise.  You should stop fretting over the stinkin' thing.

Willie