GSX1400 Owners .org

Technically Speaking => Brakes => Topic started by: VladTepes on Friday, 29 May 2020, 10:38 AM

Title: Weeping front master cylinder
Post by: VladTepes on Friday, 29 May 2020, 10:38 AM
After a ride a small amount of brake fluid seems to be weeping from the top of the front brake master cylinder.

I have tried removing the top, checking the rubber seal and refitting, making sure screws tight etc - doesn't seemed to have helped.

I can only assume then that it occurs when under pressure when brakes are being applied regularly. It doesn't seem to be the case when its just sitting overnight.


Thoughts?
Title: Re: Weeping front master cylinder
Post by: grog on Friday, 29 May 2020, 04:28 PM
No leak from mine. New seal required im  thinking.
Title: Re: Weeping front master cylinder
Post by: Blubber on Friday, 29 May 2020, 05:05 PM
Could it be that the reservoir is overfilled?

If so... there will be no room for expansion in the reservoir and it will overflow
Title: Re: Weeping front master cylinder
Post by: Hooli on Friday, 29 May 2020, 05:40 PM
The rubber seal should stop it leaking even if it's overfilled.

Clean the top edge of the reservoir and the underside of the cap, including the two tiny slots at the sides for it to vent.
Title: Re: Weeping front master cylinder
Post by: GSXKING on Friday, 29 May 2020, 06:03 PM
Check the level Mike. Have you done anything recently i.e. changed pads etc. ?
Title: Re: Weeping front master cylinder
Post by: Notty on Friday, 29 May 2020, 06:05 PM
I over filled mine after new pads it only weeped occasionally  :bugga:
Title: Re: Weeping front master cylinder
Post by: froudy on Friday, 29 May 2020, 06:35 PM
If as already mentioned you've had the cover off recently for any reason, then they do tend to weep a little. Wipe it over and see if it comes back. If it does, then you'll need to investigate further.
Title: Re: Weeping front master cylinder
Post by: Eric GSX1400K3 on Friday, 29 May 2020, 08:54 PM
Too full.  Bleed the system a lever pump or two at the caliper and should be all good. Resevoir cover off of course.
Title: Re: Weeping front master cylinder
Post by: Hooli on Friday, 29 May 2020, 09:01 PM
Just suck it out with a syringe, even easier.
Title: Re: Weeping front master cylinder
Post by: gsxbarmy on Friday, 29 May 2020, 09:10 PM
I agree with all the above - its either slightly overfull or not pulled down flat and the rubber seal is not flat. First off I'd take the cover off, take out the plastic insert and the rubber seal wipe them both down. Also with the handlebars level, just check the fluid is not above the marker within the master cylinder (yes there is one, a small mark in the alloy) - then refit, nipping up the screws on the lid. If it still weeps nip it some more. Can take a couple of goes sometimes.