Posted by JohnD [73.201.111.112] on Tuesday, October 05, 2021 at 16:01:43 :
In Reply to: B1PW master cylinder question posted by Dickie in Southwest Va. [66.171.94.228] on Tuesday, October 05, 2021 at 07:40:02 :
I cant speak for the port on the master cylinder directly, but it sounds like it is not a pipe thread, and that’s why you are having trouble sealing the threads.
Pipe fittings and plugs are tapered. The more you tighten it, the better it seals.
Brake fittings are not tapered, they bottom out against a tapered ferrule that seals them from leaks. They use a bolt thread (fine thread)
Here’s an example straight thread brake port plug for 1/4” brake tubing (not 1/4” pipe thread)