Manta A series Master Cylinder

[Bruce Hockley]

I fitted a NOS master cylinder to my A series and tried to bleed the brakes myself with a vacuum bleeder. It seemed to work but pedal wasn't great. 

When I finally got round to getting someone to help bleed the brakes manually then we quickly realised there was virtually no fluid movement. 

I removed the pipes and a small amount of fluid squirted out at full pedal to floor so I assume the seals are no good. Gone hard over time maybe?

Does the B series master work with the A or is there a suitable alternative available from another car? I am not worried about originality.

[hoobby]

Just to check did you bench bleed the master cylinder before fitting?

If you have a brake flare kit make some of these and blank off the master outputs if the master is  good pedal will hardly move and stay firm.

Edited July 29, 2022 by hoobby

[Bruce Hockley]

No I didn't bench test it as it was brand new so just assumed it would work. 

I can try your idea tomorrow to test.

[hoobby]

8 minutes ago, Bruce Hockley said:

No I didn't bench test it as it was brand new so just assumed it would work. 

I can try your idea tomorrow to test.

So long as you bleed all the air out of the master first as it can trap air inside.

if the seals are bad you should see the  level on the reservoir rise slightly as the fluid goes passed the seals.

Edited July 29, 2022 by hoobby

[Jessopia74]

1 hour ago, Bruce Hockley said:

No I didn't bench test it as it was brand new so just assumed it would work. 

I can try your idea tomorrow to test.

Sometimes crud can get into the master cylinder and get stuck behind the seals on new units. Also if it’s been sat around for a very long time, it might also have a slight surface rush on the cylinder wall that will do the same thing, let’s pressure past the lip.

lastly, and more common than you think. It was assembled wrong, with the piston or seals wrong way around.

[Paul Barrett]

I’ve had a master with seals built up wrong  before, worth checking