Slow leak from drain outlet

[flyflinger]

I'm stumped! I have a slow leak from the drain outlet tube on my '77 Globetrotter. I have disassembled the two drain valves, cleaned the seats and stems, replaced the faucet washers, and reassembled, without resolving the leak. Seats and stems appear perfect, no pitting, cracks, or flaws. There is no leakage from the city water inlet, so I believe the check valve is o.k.

Suggestions about the cause of the problem and fixes would be most appreciated!

I would rebuild all under the vanity, but just getting to the valves is difficult , and replacing the parts was a real elbow-buster !

Finally, I could just let it go, given the leak is 1 oz per hour, but the cycling water pump reminds me I have a leak!

[flyflinger]

On further inspection, under the vanity and somewhat out of sight, is an in-line valve with a flare fitting on one end that feeds into the overflow tube. I believe this is an 'overpressure relief valve', and I'm guessing it's the source of my problem.

More after further research......

[flyflinger]

It's probably a slow leak in the pressure relief valve, not shown in the '77 Service Manual schematic, but mentioned in the system description.

Now, does anyone have a part number?

[flyflinger]

So, here is the info on the part #
1/2" inlet and outlet

Airstream #000111, per Andy at Inland RV
Grainger part # 1X624, pg 4407 $26.30, from another AS Forums post.
WATTS Relief Valve, 1/2 In, Brass, M x FNPT - Relief Valves - 1X624|530-1/2 - Grainger Industrial Supply

Watts part # 530-1/2

So, it's all there if one just reads enough!