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Petock Removal Advice
Posted: Sun Nov 15, 2015 3:57 pm
by squid on a 300
I have the CW mostly dissembled. As far as removing the petcocks from the tank do you guys have any tips? I'm a little leery about putting a wrench on them after years of rust and junk accumulating in the threads and just twisting the petcock mount (Boss) right off the tank along with the petcock...
Thanks
Bob.
Re: Petock Removal Advice
Posted: Mon Nov 16, 2015 10:47 am
by Bullfrog
While appropriate caution is in order, I have doubts that either the brass petcocks or the "pot metal" petcocks can "seize" so firmly in the tank bosses that you'll damage the bosses while attempting removal. Neither the brass or the "pot metal" is known for lifetime "corrosion marrying" with steel . . . so removal shouldn't really be a problem.
It sounds like you may be concerned with gunk in exposed threads inside the tank causing a bind, again, I don't think that will be a significant issue. However, a cautious "staged" removal should address that issue quite safely. Loosen the petcock an eighth of a turn, then re-tighten. Loosen a quarter turn - retighten. Loosen half a turn, retighten 1/4 turn. Rinse/blow/brush the internal exposed threads (if there are any) as needed. Continue "staged" removal. Each loosening and retightening will tend to "flake off" any gunk on the threads.
Ed
Re: Petock Removal Advice
Posted: Wed Sep 18, 2019 5:40 pm
by matt glascock
Serendipity - almost. I just saw this while perusing old threads - almost exactly 24 hours after snapping off a frozen pot metal petcock off at the threads. Great tip Captain - thank you!
Re: Petock Removal Advice
Posted: Thu Sep 19, 2019 2:52 am
by socalhodaka
heres a link to my how to install and get your petcocks alined right on the tank
https://www.youtube.com/watch?v=aPIzn4lju3Y&t=1s
Re: Petock Removal Advice
Posted: Fri Apr 17, 2020 4:59 pm
by bcruder
I removed my wombat petcocks after almost 40 years in storage and found no interference from corrosion.
Even though I did drain the tank before storage, I first flushed it with some new gas to remove still-liquid oil and next with tri-sodium-phosphate solution to remove solid oxidized oils. Those are generally of vegetable origin and act like linseed oil based paint. Both solutions came out clear and neither found any rust inside the chrome tank. An inspection mirror confirmed that.
My tank must have straddled a production change because it had one brass petcock and one alloy petcock. NEITHER had the original screen filters and I assume those had corroded out before storage. New hoses and a modern disposable paper filter are both good insurance.
Bob