Rear Master Cylinder Sticking

[andy white]

Hello Everyone,

I have been out for a ride out today with a mate (he was on a 1150 GSA), whilst keeping up on a quite energetic twisty B road I noticed that my back brake wasn't working too well, I had to press the lever pretty hard to get any response. Although I only use the rear for about 10% of the braking, it did concern me.

At a tea and bun stop I found there to be about 12mm of play in the brake pedal before any brake force was applied (bike on centre stand, mate spinning rear wheel). Then a few more tries and there was only a few millimeters of play in the pedal.

I am assuming that the rear master cylinder is sticking, then freeing up with use then sticking again?

My Question is,

Do you think that the rear master cylinder is sticking?

Also Has anyone out there Re-Built the rear master cylinder?

Bike is a '99 1100GS ABS

Many Thanks

 

[Steptoe]

My Question is,

Do you think that the rear master cylinder is sticking?

:

It could be.
Or it could be the caliper is sticking.
Or it could be it needs bleeding.

 

[andy white]

Sorry I didn't say,

I thought it could be the caliper sticking, so i have stripped it, cleaned and re-built it.

Then I changed the fluid using a Mity-vac, no bubbles in the reservoir tube either (I have been caught out by that in the past!)

But still the same, pedal gets play in it, then goes hard, then the play comes back

I have been looking on Motoworks/bins but they dont seen to sell a repair kit.

Do you think it is the master cylinder?

Cheers

 

[Steptoe]

Do you think it is the master cylinder?

Cheers

Could be......