S4RS master brake cylinder leak!

02-01-2012, 07:28 PM

Has anyone experienced similar? slight leak/weep from around the black filling cap of the front break master cylinder? have taken it off cleaned/dried it off but still after some time comes back. Now the black paint on the cap is begining to peel. Any ideas appreciated.

rollo22 · 02-01-2012, 08:27 PM

Probably a pin hole in the Black bit or a nick in the reservoir top edge
sorry if its a bit vague

Rally · 02-01-2012, 08:33 PM

It seems to be a common problem on the standard reserviors. The black comes off most of them and most people swop them for billet lids or Rizoma canisters. Keeping the level a bit lower than the full line helps.

Flip · 03-01-2012, 09:28 PM

There's a little slot cut into the caps (clutch is the same) to allow the diaphram to work properly, if the slot gets blocked (usually through corrosion or road muck) the diaphram then 'gives' a little and allows the fluid to weep.

Worth little look and see if that's the problem, but yes they do tend to flake the paint quite easily so why not give them a quick brush over with some matt black paint while they're off.

08-01-2012, 06:47 AM

I have rizoma resevoirs and the brake leaks around the top seal regularly. The clutch never. The lid is on tight. Thought it might have something to do with how much it is used.

02-01-2012, 07:28 PM	#1
carr01 Guest Posts: n/a	S4RS master brake cylinder leak! Has anyone experienced similar? slight leak/weep from around the black filling cap of the front break master cylinder? have taken it off cleaned/dried it off but still after some time comes back. Now the black paint on the cap is begining to peel. Any ideas appreciated.

02-01-2012, 08:27 PM	#2
rollo22 Moderator Join Date: Apr 2008 Location: Moreton-in-Marsh Bike: M1100evo Posts: 1,082	Probably a pin hole in the Black bit or a nick in the reservoir top edge sorry if its a bit vague __________________ IF ALL ELSE FAILS READ THE INSTRUCTIONS

02-01-2012, 08:33 PM	#3
Rally Taking life easy........ Join Date: Feb 2010 Location: Wiltshire Bike: Other Not a Ducati Posts: 1,969	It seems to be a common problem on the standard reserviors. The black comes off most of them and most people swop them for billet lids or Rizoma canisters. Keeping the level a bit lower than the full line helps.

03-01-2012, 09:28 PM	#4
Flip Registered User Join Date: Mar 2010 Location: Beachtown Bike: M900 Posts: 2,188	There's a little slot cut into the caps (clutch is the same) to allow the diaphram to work properly, if the slot gets blocked (usually through corrosion or road muck) the diaphram then 'gives' a little and allows the fluid to weep. Worth little look and see if that's the problem, but yes they do tend to flake the paint quite easily so why not give them a quick brush over with some matt black paint while they're off.

08-01-2012, 06:47 AM	#5
spm23 Guest Posts: n/a	I have rizoma resevoirs and the brake leaks around the top seal regularly. The clutch never. The lid is on tight. Thought it might have something to do with how much it is used.