Topic: No pressure in rear brake...

[LeoLegendATL]

I just "fixed" my rear brake but have encountered a problem.  I have no pressure in the rear brake, the master cylinder pushes all the way up even when the bleed screw is tight.  I am losing no fluid either, I tried bleeding, but it seems air is leaking into the system.  or do I need to keep bleeding.  The brake slows the wheel a little bit but does not clamp, the master cylinder just bottoms out.  Any ideas?  Cb750f

[eldar]

Keep bleeding. It is possible that there is an air leak but if there are no fluid leaks, I would not think so.

[kghost]

Sounds like a blocked orifice in the resevoir. (the small orifice).

[mcpuffett]

or fluid getting past the seal internally  mick.

[eldar]

fluid seep may be possible but since there is no fluid leaking.. hard to say. Not sure about the orrifice since the lever bottoms. I would almost think there is a huge amount of air in the line but something could have been installed wrong that does not leak, but is not pushing the fluid.

[LeoLegendATL]

I took apart the rear master cylinder and put it back together cleaning everything, then as luck would have it, I torqued the head off the bleed screw in the back, great. Tried to drill it out, but now Im looking at a new caliper possibly.  Anyone know where to find one?

[eldar]

Your best source for price would be ebay or a bike junkyard. Otherwise if you can find one that fits for new, it will be hard and costly.

[scondon]

What year is your bike? I may have some 75-76 rear caliper bits about and most definitely have 77-78 calipers. F models.

[LeoLegendATL]

What year is your bike? I may have some 75-76 rear caliper bits about and most definitely have 77-78 calipers. F models.

75f, that would be great, let me know what you can do.