Thread sealant on brass

[Esser]

In my previous life, we never used thread sealant on brass fittings as the material is soft enough that the threads deform creating a seal.

The kitfox manual specifies sealant on the fittings coming from the master cylinder but does not say anything about the brass fittings into the gear legs, calipers, and cylinders. Am I correct to assume that thread sealant is not required due to the fittings being brass?

[jrevens]

I think you should use a good sealant, Josh. There are several reasons why. In my opinion, if you are tightening a conventional tapered pipe thread assembly tight enough to deform the threads to the point of a perfect dry seal you are over-tightening them. When tightening, intimate contact between the tapered surfaces of the mating threads may seal if the surfaces don’t have too many scratches or imperfections, but the design of the thread is such that contact does not, or should not occur at the very point of the threads. The sealant will fill and seal this tiny pathway. Secondly, the sealant provides important lubrication during the tightening, as well as a positive seal to keep any moisture from entering - especially important with dissimilar metals. Having worked as a journeyman pipefitter in the refrigeration trade for many years, and studying as an engineer, that is what I was taught.

[Esser]

Thanks John, I will add sealant.