1 cannot bleed rear brake Mon Jul 01, 2019 2:21 pm
tinyspuds
Life time member
Follow on from replacing OEM master cylinder with a Chinese one.
Pride goes before a fall” section.
When I put everything back together I over did the pedal adjustment and the brakes were everything I hoped for. Except the over adjustment resulted in the m/c piston being unable to return fully. In turn this meant that the caliper pistons couldn’t retract properly.
In turn this meant that after a 10 mile ride I experienced a loss of forward movement then stall.
Rear brake was locked on and smoking like a damp bonfire.
Caliper dismantled, plastic cover discarded, melted seals replaced, everything cleaned, greased and re assembled. Now I cannot get back pressure into the system which is the problem I had before - which is why I over compensated on the adjustment (without thinking it
through) in the first place.
I’ve flushed all the boiled fluid, can get good pressure at the m/c outlet, and at the caliper end of the stainless steel line but can’t make it carry through to the caliper.
Both pistons move, both pistons retract when pushed, both pistons will lock on when pumped but there is a barely noticeable increase in resistance at the pedal and the pad grip isn’t exactly snapping turtle.
I have used both the hand pedal pump method and the vacuum assisted. Run through litre and a half of fluid and spent 6 hours without progress.
Any thoughts?
Pride goes before a fall” section.
When I put everything back together I over did the pedal adjustment and the brakes were everything I hoped for. Except the over adjustment resulted in the m/c piston being unable to return fully. In turn this meant that the caliper pistons couldn’t retract properly.
In turn this meant that after a 10 mile ride I experienced a loss of forward movement then stall.
Rear brake was locked on and smoking like a damp bonfire.
Caliper dismantled, plastic cover discarded, melted seals replaced, everything cleaned, greased and re assembled. Now I cannot get back pressure into the system which is the problem I had before - which is why I over compensated on the adjustment (without thinking it
through) in the first place.
I’ve flushed all the boiled fluid, can get good pressure at the m/c outlet, and at the caliper end of the stainless steel line but can’t make it carry through to the caliper.
Both pistons move, both pistons retract when pushed, both pistons will lock on when pumped but there is a barely noticeable increase in resistance at the pedal and the pad grip isn’t exactly snapping turtle.
I have used both the hand pedal pump method and the vacuum assisted. Run through litre and a half of fluid and spent 6 hours without progress.
Any thoughts?
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1985 BMW K100RT + Hedingham HUB and LL’s. VIN 0028106.
1986 K100RS in boxes. VIN 0141918.
1954 Royal Enfield 350 Bullet. Original.
2000 Hayabusa with Charnwood chair, Wasp forks and EZS wheels.