Leaking tank petcock ?

[olosh]

Hello. My tank petcock is leaking a bit, I think from the internal washer rather than from the seal against the tank. Anyone know if it is rebuildable, and what seal I will need ?

[alpo]

The internal o-ring can be replaced. Mine was rotten and I replaced it with a nitrile one from a set I got at Harbor Freight. I don't remember the size, but the entire set of o-rings was only a few bucks.

[olosh]

OK cool, so it is just a simple o-ring then ? not a fancy washer with 2 or 4 holes like many petcocks ?

[alpo]

Yep. A single o-ring around the metal piece of the valve that turns the fuel flow on/off. The valve itself is beneath the metal piece. Gently pry up the sides of the retainer to take it apart. There is a spring between the metal piece and the valve, so take it apart slowly.

[olosh]

Cheers. Should be a piece of cake.

[tobyd]

Mine did this, I replaced the o-ring with a nitrile-70 2mm CS x 10mm ID from ebay and its worked a treat.

I bent the retaining plate (the shiny bit) tangs (the bits that clip to the petcock) in a smidge when I reinstalled it the second time.

the first time it was a bit loose and came undone and made a mess.

[olosh]

Perfect, that is exactly the information I needed. Many thanks.

[tobyd]

It's probably some useful info to get in the Wiki really. I've replaced a couple now and they seem to be alright. If you can confirm it works for you I'll see about putting a page in for user-approved replacements perhaps?

[olosh]

Watch this space ! I ordered 10mm ID 2mm CS Nitrile. I was tempted to upgrade to Vitron but didn't bother in the end.

[tobyd]

I think mine were less than 2GBP delivered next day. Nitrile-70 is fine with petrol. I think age probably haggers the things after a while and they stick to the petcock body then tear the next time anyone wants to turn off the petrol.

[olosh]

Yeah, that makes perfect sense. Mine was about £1.32 or some-such. Hope it will arrive tomorrow, then I will fit it and report back.

[olosh]

Yup, easy fitting and 10mm ID 2mm CS seems about the right size. Old o-ring was perished, cue rant about ethanol in petrol.......