Front brake master cylinder rebuild kit?????

G5RJO

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Anyone found a source for a front brake master cylinder repair / rebuild kit?

(1200 adventure - 2008, 100,000 miles and it's due.....).

Sherlocks and Motorworks don't list them, BMW stealer wants to sell me seals with a master cylinder round them...:nenau

Roger.
 
Have you looked to see if a 1200 RS / RT or even a K series bike or an 1150 is the same?
 
BMW do not sell master cylinder seal kits. Bleed the brake with careful lever movements. If the air is removed then your'e good to go. :thumb

If not, the cylinder is probably toast anyway so bite the bullet. :rob
 
BMW do not sell master cylinder seal kits. Bleed the brake with careful lever movements. If the air is removed then your'e good to go. :thumb

If not, the cylinder is probably toast anyway so bite the bullet. :rob

You Sir are the type of customer BMW perfer. Pay for a whole new master cylinder when a seal might do. "We tried to bleed it didn't work so you need a new one". JJH
 
You Sir are the type of customer BMW perfer. Pay for a whole new master cylinder when a seal might do. "We tried to bleed it didn't work so you need a new one". JJH

I Resemble that comment. :D

I have tried to find a source of new seals and given up. Nobody can help and Brembo weren't offering to let me fumble through their store rooms for anything compatible.

At 50K miles, bleeding the brake normal style always sucked in air. Moving the lever slowly, especially on the back stroke, and then tying the lever back overnight cleared the last fine bubbles. The front brake has been fine ever since. Now at >70K miles.

Back brake got a new (used) cylinder from Sherlocks because the original was corroded and well ****ed.
 
I Resemble that comment. :D

I have tried to find a source of new seals and given up. Nobody can help and Brembo weren't offering to let me fumble through their store rooms for anything compatible.

At 50K miles, bleeding the brake normal style always sucked in air. Moving the lever slowly, especially on the back stroke, and then tying the lever back overnight cleared the last fine bubbles. The front brake has been fine ever since. Now at >70K miles.

Back brake got a new (used) cylinder from Sherlocks because the original was corroded and well ****ed.

It was the asumption that the cylinder is probly toast anyway. It is a pain that there seems to be a deliberate policy not to supply parts to repair cylinders and many components nowadays. BMW and other manufactures are laughing all the way to the bank. JJH
 
I have once read somewhere that a KTM kit is the same... But can't remember which or where I read it.
It would be a useful find...

Sent from my Moto G (4) using Tapatalk
 
It was the asumption that the cylinder is probly toast anyway. It is a pain that there seems to be a deliberate policy not to supply parts to repair cylinders and many components nowadays. BMW and other manufactures are laughing all the way to the bank. JJH

It's brakes of course - cant be too careful. Let's scare the punters.

BMW are the same with brake disc wear limits. My MoT tester always checks or cracking between drilled holes in the discs. He will accept them well below BMW's wear limit as long as here is no signs of cracking. My rear disc ran for 2 at least years with wear below what BMW would say is acceptable and 100% no problems. Of course there have to be limits but take it too far and perfectly usable kit gets thrown away.

It would be good to find the source of a compatible rebuild kit for the master cylinder.
 
Has anyone tried to fit a master cylinder of another make of machine. I find that after the servo removal, two finger braking is a bit too much effort.

Got me thinking . Would a big master cylinder and lever assembly of a race rep bike like an R1 have any more benefit.
 
Has anyone tried to fit a master cylinder of another make of machine. I find that after the servo removal, two finger braking is a bit too much effort.

Got me thinking . Would a big master cylinder and lever assembly of a race rep bike like an R1 have any more benefit.

Yes. Front brake master cyclinder failed on a trip round the Lake District. Fitted a whole master cylinder and lever from a Kawasaki touring bike (not sure of the model), the handlebar diameter was the same and the fitting to the brake line matched. Worked perfectly (and felt much better that the BMW version which I replaced it with. Only issue is the mirror mount.
 
Has anyone tried to fit a master cylinder of another make of machine. I find that after the servo removal, two finger braking is a bit too much effort.

Got me thinking . Would a big master cylinder and lever assembly of a race rep bike like an R1 have any more benefit.

A bigger bore master cylinder will make the brake feel "wooden" as the effective leverage (hydraulic ratio) is reduced. Go for a smaller bore if you want more sensitivity at the lever.
 
Cleaned up my rear master cylinder, 2008 GS, and I can see why there is no seal/piston kit. It's not like other master cylinders I have seen. There is no retaining circlip behind the dust boot, just the top of the piston. It must be retained by a fastener that is hard to access - I would imagine the front might be similar, although I haven't removed it to look. I cleaned it up, lubricated the bore and blew out feed side (as had suspected slightly sticking caliper still after rebuild). Master cylinder seemed to work well and no leaks. All working again now as it should. Cost a few quid for some brake fluid and replaced reservoir hose which I had lying around. Given the lack of rebuild kit it makes sense to change fluid regularly and to clean up master cylinders periodically
 
Cleaned up my rear master cylinder, 2008 GS, and I can see why there is no seal/piston kit. It's not like other master cylinders I have seen. There is no retaining circlip behind the dust boot, just the top of the piston. It must be retained by a fastener that is hard to access - I would imagine the front might be similar, although I haven't removed it to look. I cleaned it up, lubricated the bore and blew out feed side (as had suspected slightly sticking caliper still after rebuild). Master cylinder seemed to work well and no leaks. All working again now as it should. Cost a few quid for some brake fluid and replaced reservoir hose which I had lying around. Given the lack of rebuild kit it makes sense to change fluid regularly and to clean up master cylinders periodically

Mine had the early rear master with a very thin dust seal. The piston was just jamming at random and holding the brake on. A replacement (later model) used master from Sherlocks did the job for not much cost. The cylinder looks identical but has a much better dust seal. I filled that with red rubber grease and all has been well.
 


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