brake master cyl problems

[Linton]

Hi all need some advise., I fitted a new non genuine b/m/cyl about 2 yrs old now prob about 5k done in the car.

the front reservoir is losing fluid no leaks but have noticed the rear is filling up by itself (bypassing somehow). watching the front reservoir when applying brake engine off, a  very violent squirting of fluid in the chamber.

any ideas? another new cylinder. I have always felt the brakes were not 100% and felt the need to pump but the peadal doesnt come up any higher, has good solid feel

[dat2kman]

Tandem masters are designed with ports that link each res down into the piston assy.

As you press pedal, ports get blocked off, and then the further movement of the pedal pressurises the brake lines.

It may be, that initial pedal press that is allowing some fluid from one, to get past seals, and go up into other res.

This could happen if the pushrod is set back too far,, ie your in-cabin pushrod adjustment is too far back.

 

Other possibility is the internal seals between the front piston area and rear piston area are not doing what they should be. This is more likely. And there could be slight scoring on walls.

Might be able to buy a M/C full seal/piston rubber kit, for it, if no scoring.

Otherwise stainless sleeve it, or r&r.