K75 / K100 Front Master Cylinder seals

[Quiltzig]

Can you buy the seals for the MC as a kit or do you need to get the whole piston with seals kit? Seems that latter is rather expensive.

[Quiltzig]

It’s the 13mm MC with the square plastic reservoir and 3 screws securing the cover - am on mobile at moment so can’t find part number easilymoment so

[alabrew]

Best I know is that you can only buy the piston with the seals installed.

[KIWIDON]

Last one I purchased was from BMW in Auckland as needed for daily rider and was close to NZ $180 for overhaul kit.
Can have for 39 Pounds ex UK so including freight (you will no doubt order other consumables) it will work out far cheaper. Purchased my rear cylinder kits for both K's from the UK.

[Martin]

There is a slight possibility if you know the dimensions of the cups that you might be able to source them from here. He is a nice guy and extremely helpful, I've sourced master cylinder boots from him. He also sleeves Brick front master cylinders, and once done a set of cups is around $10.00 AU. He doesn't like doing rear cylinders as the plastic part the reservoir connects to has a habit of breaking on removal. The end result he has to make a new one out of brass inflating the cost.
Regards Martin.

Boots and cups supply[1].jpg (55.42 kB . 768x576 - viewed 350 times)

[stokester]

tills.de also has a full kit...

https://www.tills.de/brembo-piston-13mm-repl-bmw-32722302356.html

I found their replacement fan assembly first-rate, shipping reasonable and fast.

[Quiltzig]

Thanks to both of you for your helpful replies.
This forum is great!

[Martin]

If he can supply cups, they can be hard to fit over the piston. He recommended using a couple of well linished screwdrivers with no sharp edges and lube well. Any sharp edges can cause nicks that could cause leaks or tears.
Regards Martin.

[natalena]

Got a 13mm piston/spring/bushings assembly from Motobins in the UK for 50 pounds. Shipped amazingly fast to the "colonies" and was a direct fit that eliminated the nasty dribble.  It's the first thing that pops up on their website under Brakes/Front. Good luck

[szabgab]

Can you buy the seals for the MC as a kit or do you need to get the whole piston with seals kit? Seems that latter is rather expensive.

Apart from ordering a new set,  did you try to clean them?   Many times all it takes is a godd scrub down,  it certainly helped my leaking front MC.  If that does not help,  at least you'll see what's at fault and what needs to be replaced

[schrocketeer]

A full piston with seals option is $63 US (plus shipping) from Beemer Boneyard https://www.beemerboneyard.com/32722302356.html
My install of this a couple of months ago on my '85 K100RT was pretty straight forward.