Master cylinder bench bleed - Necessary?

[chemeng]

Getting ready to swap out the fruit jar on my '65. The master cylinder instructions say to bench bleed the M/C before installation. Is this really necessary if I have a power bleeder? Might take some extra brake fluid, but after 40+ years a little extra flush won't hurt.

TIA. Mike

 

[dodgestang]

Yes you need to bench bleed it. Even with 'power bleeder' it will take forever to suck all that air through your lines.
Bench bleed it, install it, then flush your lines with the new fluid.

 

[chemeng]

Bench Bleed

Thanks Dodgestang. My bleeder works the opposite way, I pressurize a cannister and force fluid through the system, no vacuum. Should have learned by now there are no shortcuts unless you want to do it over! Bench bleed it is.

Mike