Triumph Repair: master cylinder / slave, thread gauge, english measure

Question
I got a new master cylinder for the clutch on my 1965 spitfire and when I installed a new line at the Master to the slave cylinder it leaks at both connections.  I did have a hard time matching the ends of the new lines to the threads in the master and the slave.  I think it's 3/8" but it must not be exact because it leaks.  Is the old english measure slightly different that the 3/8" from NAPA?  Where should I get a line and bleeder?

thanks
John

Answer
Hi John,

I don't think the line threads were BSF or Whitworth on the 65 Spitfire. But you do need to examine the ends of the pipes because there are two different types of pipe ends. One is a flare and the other is a bubble flare. As I remember the Spitfire used a bubble flare. The bubble flare is a "Male" end on the pipe and the Flare is a "female" end on the pipe. Be aware that NAPA sells metric too and the 65 Spitfire did not have any metric fittings on it. Nothing on a 65 Spitfire was metric and the only British nut I ever found on one is the generator pulley nut.  

You should be able to hand run the nuts in several threads by hand. If you don't have a thread gauge take the new one off and hold the old one and the new threads up to a light and fit them up against each other to see if they are the same threads.

Howard