rear brake system bleed

[uneasy rider]

Trying to bleed the rear brake on a 1975 Commando. I are using a vacuum bleeder connected to a good compressor. No fluid is dripping anywhere when I pump the brake pedal, no visible leaks, and no fluid is being drawn thru the system with the bleeder pump. Possible bad master cylinder ? any other suggestions ?

Thanks

 

[concours]

Vacuum bleeders suck....


...air into the system around the rubber cups.



Use a pressure bleeder.

 

[L.A.B.]

I've only ever bled it in the normal way.

Possible bad master cylinder ?

If the master cylinder and caliper haven't been rebuilt in the last ten years or so and the hose replaced, then it's probably overdue.

 

[uneasy rider]

Thanks, air into the master cylinder, that worked.