K11 Owners Group

Bondie · Posted: Thu Jan 23, 2020 7:12 pm Post subject: Front brake help please!

Hi Guys & girls

Just tried replacing my 92 K1100LT's front brake master cylinder piston, had a leak which appeared to come from there.
The replacement part came in a repair kit x BMW 3272 2 332 037.

The new piston has seals which appear to be bonded and not removable, the widest part of the new piston body is 1mm wider than the existing piston so will not fit into the master cylinder.

The existing piston also has 2 silver metal bands on the in side of the seals, next to the seals on the "raised" part of the piston, the seals can be removed & replaced from & to the piston.

The master cylinder does not appear to have a liner of any description fitted in the bore.

Unfortunately I have put the old piston back on the bike so am unable to post a photo of it.

Has any one else had a similar experience?
Any thoughts will be gratefully received. I don't really want to replace the master cylinder.

Cheers
Bondie
_________________
"The only thing I know is that I know nothing"

Scott_Anderson · Posted: Fri Jan 24, 2020 7:35 am Post subject:

Can you measure the diameter of your new piston. It should be 20mm.
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Ride safe.

1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

Jim · Posted: Fri Jan 24, 2020 7:00 pm Post subject:

Did it come in a box or a bag with a part number?
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Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

Bondie · Posted: Sun Jan 26, 2020 6:19 pm Post subject:

Hi Scott, thanks for the reply, i did measure it but didn't take a note of it, just that there is a 1mm difference, i had to take them to an engineering workshop to borrow a vernier.

Hi Jim thanks for the reply, yeah came in a BM bag with the part number 3272 2 332 037 from the local BM parts supplier/dealer, its definitely genuine.

This is very odd?

Cheers
Bondie
_________________
"The only thing I know is that I know nothing"