Fuel Drains

Hi All

I have some galling on my fuel tank water(sump) drain thread and will tap it out but firstly I need to know the thread size. Thanks

go easy!

1/8" NPT. Don't go too deep, else the fitting will be ruined. That thread set is tapered.

Always use lube on aluminum threads. Fuel Lube would be the best on this fitting. Fuel Lube is beeswax....

Carry on!
Mark

Thanks F1Boss

If the galling has not severely distorted the threads, before you have at it with a tap, take a steel fitting and lube it up with fuel lube and use it like a tap, backing off every 1/4 turn, then advance, repeat.
This is a little gentler way of restoring the aluminum threads if they are not too bunged up.