Replacing a master cylinder


#1

Last year I bought a pressure bleeder for flushing and replacing brake fluid (well worth the $50).



I’m going to be replacing a master cylinder soon and will use it to bleed the system. I’ve replaced M/Cs many times before and I have always bench bled the cylinder first and then bled the system the old fashioned way.



My question: Is it necessary to bench bleed the cylinder first if I’m using a pressure bleeder? I vaguely recall reading somewhere that it is not, but I’m not sure.



Thanks!


#2

If the master cylinder is properly bench bled and installed no further bleeding is necessary.


#3

No. The master cylinder doesn’t require bench bleeding before it’s installed. That’s one of the advantages of using a pressure bleeder.

Tester


#4

What about the air you introduce into the lines when you disconnect them from the old master?


#5

As long as you do not crack open any other bleeders its no problem.

After installing the m/c and connecting the lines you can bleed them and all will be good.