Sprint St 1050 - Front Master Cylinder Rebuikd Kit

Hubaxe · May 14, 2020

Hi all,
I create another thread to keep topic search clear.
My front brake is a bit spongy, even after brake bleed. I suspect the master cylinder needs a rebuild. Not that surprising on a 15 years old bike.
Trying to search the kit on the web, I can't find a clear match between the bike and proposed kits (often labelled "unbranded").
I try to find genuine NISSIN part. The best match I could find is 14mm rebuild kit Reference MCBK14.
Can someone confirm ? That would help a lot.

trudd · May 14, 2020

There are two different sizes of master cylinder fitted to the Sprint. 5/8" or 14mm. The master cylinder has some markings which will state which one you have.

These guys sell both: https://www.triumphparts.co.uk/prod...s/sprint-st-1050-gt/brakes-sprint-st-1050-gt/

But if you want genuine 5/8": https://www.fowlersparts.co.uk/part...vin-208167-/front-brake-master-cylinder-hoses

Some of the bikes were known to have sticky pistons in the calipers. When I got my Sprint I had to pump the brakes to use them. I solved this with the Teflon coated pistons from a Daytona. It's fairly well documented if you search

Hubaxe · May 19, 2020

trudd said: ↑

There are two different sizes of master cylinder fitted to the Sprint. 5/8" or 14mm. The master cylinder has some markings which will state which one you have.

These guys sell both: https://www.triumphparts.co.uk/prod...s/sprint-st-1050-gt/brakes-sprint-st-1050-gt/

But if you want genuine 5/8": https://www.fowlersparts.co.uk/part...vin-208167-/front-brake-master-cylinder-hoses

Some of the bikes were known to have sticky pistons in the calipers. When I got my Sprint I had to pump the brakes to use them. I solved this with the Teflon coated pistons from a Daytona. It's fairly well documented if you search
Click to expand...

As I was thinking about the U link between right/left calipers could be an issue to properly bleed the brake, I went on and redo the process. It's now ok. Looks like I saved a MC rebuild.