Front brake master cylinder question

[Disaster Area]

I suspect that I'm out of luck on this one, but will ask for confirmation:

Will the front brake master cylinders from an 1150 fit onto an 1100?


I'm asking as new ones appear to be very expensive and decent second hand ones are like unicorn droppings...

 

[DrFarkoff]

Will the front brake master cylinders from an 1150 fit onto an 1100?

You do know there is a repair bobbin for the 1100 one don't you ?

I suspect you have a leak and thats why you need to change ?

 

[DrFarkoff]

Replacement "bobbin" basically the piston with seals Part Number 20 Brake repair kit 32722332037 LINKY TO DIAGRAM AND Part Numbers

BUT Order Part 8 Which is 32722310756 as the old one will be swollen and useless

Its a simple operation

Protect your tank from leaking fluids (If I am not removing it I spray Mr Sheen on it and stick a plastic bag over the spray

Undo the Pivot Bolt on the lever

Remove the soggy boot

Find the small 3mm headed allen key on the body of the cylinder and remove it AND retrieve the alloy washer between it and the housing(Its the stop screw that prevents the piston popping out!)

The piston should come out but you may need to spray it with hot water to dissolve those salt crystals

I have a set of Micro honing stones so I polish the bore before fitting the new bobbin

Last thing before fitting the new bobbin

there is a much smaller hole inboard of the one at the base of the fluid reservoir Make sure it is clear that is the return flow (And how the air gets out)

Lube the bobbin

Pop it in and Fit the stop screw with the new alloy washer You just want to nip this screw up Once you need to apply ANY force just one eighth of a turn further

Refit the lever and same thing Be gentle its all only light cheap alloy!

To bleed half fill the fluid and tap the brake lever to make it move in about 5mm rapidly about 10 times and stop and you will see a scoosh of tiny air bubbles coming out (Any more travel than that and you will scoosh fluid out! like a water pistol)

 

[Disaster Area]

I've fitted a repair kit and it still weeps. Not a drip, but if not used for a week or so there's a pool of brake fluid on the plastic hand guard.

 

[DrFarkoff]

I've fitted a repair kit and it still weeps. Not a drip, but if not used for a week or so there's a pool of brake fluid on the plastic hand guard.

Sounds like you need to Hone the bore or double check for scratches

Is there anyone near you who may have the equipment or as I have in the past when I did not have my mini hone was to split abit of half inch wooden dowel and use some 800 W&D through the split as the polishing media

You could use an 1150 one but you would need to fit the switchgear and rewire a connector as well