Petcock lube....

[OldSchoolBully]

I have a feeling that title will get some interesting hits on google, cos I damn sure wasn't for typing it into the search engine. Anyway, the bung cover on my tank had to be cut off with an angle grinder and I inserted a standard 3/8 NPT petcock. To get that puppy in required vice grips and essentially destroyed the chrome on the nut said petcock. I have another on order which I plan to be a little ore gentle with, heat the bung threads etc., but is there an acceptable lubricant/oil to help the process? WD40 was as useful as tits on a boar last time.

[felon]

royal purple assembly lube.

[OldSchoolBully]

Unfortunately we don't have too much of that this side of the ocean. Will a standard assembly lube suffice?

[felon]

yep. fuck it, run it.

[Ember]

Try engine oil, Marvel Mystery oil, 2-cycle oil. If it is that tight, you may have a different thread on the petcock. Unless that is obvious and why you are asking for lube, haha.

[OldSchoolBully]

Appreciate the help. Cheers.

Try engine oil, Marvel Mystery oil, 2-cycle oil. If it is that tight, you may have a different thread on the petcock. Unless that is obvious and why you are asking for lube, haha.

I was trying to come up with a less degenerate sounding title, but fuck it. Haha.... The petcock is tight because I lost about half an inch of the thread when it was ground off. So it's actually being pushed in further than it should. Plus it seems to me some of the petcocks are set at 3/8 NPT and then the chrome is added cos that shit just shaved right off as I put it in.

[Ember]

Try running a tap through the bung. Non tapered. See if that helps. First thing I always do when something fits too tightly is to run a tap through to clean up the threads. May want to run a die over the petcock threads as well.

[perezmaximus]

maybe some anti-seize compund.

[jamesgs4]

Try running a tap through the bung. Non tapered. See if that helps. First thing I always do when something fits too tightly is to run a tap through to clean up the threads. May want to run a die over the petcock threads as well.

NPT threads are tapered, so running a standard tap through it will fuck it up.

[killkill]

jamesgs is right, find yourself a 3/8 npt and run that in there... you can open some of the treads up more so you'll get your petcock in further before it tightens down due to the taper in the thread.

[OldSchoolBully]

Thanks folks. Seems time and patience was the key. With some standard oil, a pair of gloves and lot of swearing and smoking I worked the new petcock into the thread. Still a few turns to go to get it right in there but it seems the petcock not the thread was the issue. The threads seem to need worked a little. Because after working it in there slowly it is now easy to remove and replace.

[Hooligan80]

Appreciate the help. Cheers.



I was trying to come up with a less degenerate sounding title, but fuck it. Haha.... The petcock is tight because I lost about half an inch of the thread when it was ground off. So it's actually being pushed in further than it should. Plus it seems to me some of the petcocks are set at 3/8 NPT and then the chrome is added cos that shit just shaved right off as I put it in.

Am I that fucked up in the head, or did this just sound like some freaky porn accident like the title sounded like some weird sex shit?