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R100RT Brake Master Cylinder Rebuild

b25bsaboy

b25bsaboy

New member
With my on going issues with the spongy brakes I believe I will be having to rebuild the master cylinder. Further inspection and reading what I can, I fail to see if the master cylinder body is a seperate part of the control lever or is it all one piece. If it is separate, can it be serviced leaving the twist throttle in place on the handlebar.

Has anyone documented with pictures how to take this apart, inspect and do a reassembly of the unit?
 
b25bsaboy said:
Not to be silly? Where?
Click to expand...

Where the reservoir attaches to the main unit.

Undo the brake line.

remove 2 small screws.

reservoir and plunger assembly will detach.

make sure you get the right size rebuuild kit, there are different diameters.

you will need snap ring plyers.

you might loose brake fluid so watch your paint.
 
DARRYL CAINEY said:
Where the reservoir attaches to the main unit.

Undo the brake line.

remove 2 small screws.

reservoir and plunger assembly will detach.

make sure you get the right size rebuuild kit, there are different diameters.

you will need snap ring plyers.

you might loose brake fluid so watch your paint.
Click to expand...

That makes perfect sense. Thank you!
 
Reservoir attaches to aluminum base with one screw. Screw may be a phillips or a star-type. Put a new "O" ring on the reservoir plastic part which fits into the base, Before putting the "O" ring on soak it in clean brake fluid for a few minutes. Also rub a bit of brake fluid into the cylindrical part o f the base where the "O" ring will slide. Otherwise it may not seal properly. Been there; done that. Leaked the first time I did the job. After pre-lubing the "O" ring; problems solved!
 
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