Petcock being a petpain

[ZacharyB]

I don't get it,

With fuel coming in the upper tube ("on") the petcock weeps from the spigot. I checked the o-ring on the plunger and it's exactly the same size as the original. In fact, I tried both o-rings, no dice. I stretched the diaphragm spring for extra tension, still leaking. What's going on? Sucking on the vacuum end to open the plunger valve of course yields more fuel flow. Also leaks in "reserve" position.

For a second I thought it might be the wavy metal retaining ring that puts force on the four passageways' gasket. But no matter how tightly I screwed in the petcock face plate screws or how centered the ring was, it still leaked.

With fuel below the level of the "on" tube it seals fine.

Stumped! I may still need this petcock if the pingel I ordered ends up overfilling my bowls due to misadjusted float levels.

[kkesler]

One of my petcocks like the one you posted was doing the same thing after I put a rebuild kit in it. I took it back apart, smacked the piston a couple of times with the butt of a screwdriver, then put it back together. Drip free for 10k miles now.

Frustration yielded results for once.

Kurt

[ZacharyB]

Wow, what do you think the hitting did that fixed it? Center it in the passageway more?

[kkesler]

No idea. It was about to go in the trash and be replaced with a Pingel, so I had nothing to lose. Felt good to open it up and whack it, felt even better when it worked after I did it. Only thing I can guess is that the spring tension was not quite enough to close it up, and whacking it bent the disk enough so it sealed.

YMMV, don't try this at home, etc. etc.

[Anonymous]

Re: Petcock being a petpain

For a second I thought it might be the wavy metal retaining ring that puts force on the four passageways' gasket. But no matter how tightly I screwed in the petcock face plate screws or how centered the ring was, it still leaked.

That wavy ring goes on the outside of the valve piece that has the "handle" and the O-ring, just under the plate that secures it to the petcock assembly. Be sure that O-ring is new and seals correctly.

Just went through this with a rebuild kit. I put the wavy ring in the wrong place first. It leaked.

[ZacharyB]

Are you referring to the o-ring that lays in the groove on the handle piece? I don't have a different o-ring at the front of the petcock except for that one.

http://tinyurl.com/a2n7k

What is #2 in this picture? If that's not the recessed o-ring in the rotating handle piece then I'm missing it.

But I do think that my problem is with the plunger and not the front (face) of the petcock. It does not leak except out of the spigot.