Hayes Nine Brakes - Master Cylinder Leak

EarlofBarnet · Apr 19, 2013

I was bleeding my Hayes Nine brakes last night and the levers master cyclinder cover is now leaking where the bleed bung goes. Looks like this is a common issue and its the rubber seal that tears slightly. There doesn't appear to be a replacement listed on the suual sites (or on Hotlines). Is there a way to bodge this? Was thinking of a small screw with a rubber seal, similar to other Hayes brakes. Or superglue the bung in to seal it (although brake fluid may corrode it?).

Any words of wisdom greatly appreciated.

Matt

stewlewis · Apr 19, 2013

This bit?
http://www.chainreactioncycles.com/Models.aspx?ModelID=7475

That includes the bladder, the bung plugs are available separately too.

EarlofBarnet · Apr 19, 2013

That's the one, but CRC have discontinued it.

stewlewis · Apr 21, 2013

I tend to find Nines pop up on here or Ebay for spare a repairs quite often. I'd bodge to bleed plug as you say and then keep and eye open for a set for spare n repairs to pinch a bladder.

EarlofBarnet · Apr 21, 2013

It's a right pain. Nothing wrong with it at all, apart from it weeping from the bled hole. Bought a bleed screw for another Hayes brake hoping it'd screw in and do the job, but its slightly too small. Think Hayes have discontinued the proper replacement part too. As you say, will have to see if if can pick up a spare from somewhere.

stewlewis · Apr 21, 2013

So it's the hole in the rubber bladder that the bleed plug sits into that's enlarged?
I'd be tempted to take out the bladder, seal the hole completely with rubber cement, a bit of rubber, glue, something......?
And make a new smaller hole.

http://www.bikebrakemall.com/hayeshfx-9-master-cylinder-reservoir-cap-br307z03-part

EarlofBarnet · Apr 21, 2013

That's the one. The hole must enlarge as its used for bleeding etc, to te point web it won't deal against the little bung. It can be bled without using the hole, so if I can deal it up then should still be fine going forward. I was just worried that the brake fluid would corrode the sealant over time. Don't want brake fail part way through a downhill run! Might try supergluing the bung in place and see how it holds. Seems a shame to buy a new brake for such an annoying problem :S

EarlofBarnet · Apr 21, 2013

All sorted, phew! Took the top cap off the reservoir and removed the seal. Turns out there is a little neck to the seal that sticks through the cap, and the rubber bung sits in this. Pushed it back through and popped back in the rubber bung and it leaks no more! Over the moon! Re-bled it (with cover removed), refitted everything and jobs a good one.

Ewan50 · Sep 28, 2018

Re:

... found some hayes 9 bleed plugs on ebay from moat_vale_cycles, they appear to have plenty in stock

Hayes Nine Brakes - Master Cylinder Leak

EarlofBarnet

stewlewis

EarlofBarnet

stewlewis

EarlofBarnet

stewlewis

EarlofBarnet

EarlofBarnet

Ewan50

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