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View Full Version : S4 front brake problem - master cylinder seals?


itiejim
12-06-2016, 05:00 PM
I've got what I believe to be a minor leak in my front brake system. I replaced the caliper seals recently and have been able to get a decent brake lever. However, over a period of weeks the brake system seems to suck in air, resulting in a soft lever and another bleed...

There are no signs of any fluid leaks anywhere and the level doesn't go down. I've tried all the obvious things like tweaking up the bleed nipples and banjo bolts but the problem persists.

So - are there any other areas I should check, or can someone point me in the direction of a decent seal kit for the master cylinder?

Mr Gazza
12-06-2016, 05:19 PM
Sounds like a classic Master cylinder seal failure to me.

I would go straight to Moto Rapido for something important like that. They will be able to identify the master type and send you the correct seal kit.

itiejim
13-06-2016, 07:56 AM
Thanks, I'll give them a call.

itiejim
13-06-2016, 08:01 AM
Moto Rapido can only do a complete MC apparently - £165 ��
Does anyone know the spec so I can speak to Aprilia / KTM to find a matching seal kit?

jerry
13-06-2016, 07:57 PM
bevel heaven can probably supp;y it

Mr Gazza
13-06-2016, 09:11 PM
Sorry Moto Rapido couldn't help...Unusual for them.

These people might be worth a call?

http://www.biketorqueracing.co.uk/brakes

Or possibly DemonTweeks?