hayes leaking at caliper

I'm running 2001 Hayes Mags, rebuilt in March, 10 rides on them now, EBC gold pads, Goodridge hoses, Envy levers.

One thing I noticed is that now that there is no give in my hoses or levers, my calipers flex like mad. Bolts are tight though.

A week ago, I noticed a significant loss of braking power, and a lot of squealing form my front Hayes. Tonight I cleaned the rotor and put new EBC golds in thinking that it was just something I had rode through. Put everything back together and gave the lever a huge squeeze (while the bike was in the stand) to check for leaks, just in case, and nothing.

So the system worked great until I was speeding along later and went to lock my front wheel, and grabbed the brakes hard. For a second the wheel locked up, but then I got squealing and next to no power.

When I came to a stop there was a lot of DOT4 dripping from inbetween the caliper. I cleaned her up. And squeezed the lever. No leak. It only leaks when stopping hard with speed.

In all my years of using Hayes I've never seen seals go this fast, so I think maybe it's excessive caliper flex that is causing the leak. Any ideas?

my friends hfx-9 is kinda bubbling out of the caliper and his break has lost power almost total poewer and we cant figure out whats wrong with it.

The seal between the two caliper halves is what is leaking.

It needs to be taken apart, replaced, and then re-bled.

Or, just send it to Hayes… and have them do it :thepimp:

-Matt

hmmm. seals? i thought the only thing that's in between the 2 halves is an o-ring of some sort. is that the seal you're talking about?

i guess eventually something's gonna give? makes sense.

Dunno, I've been hearing about a lot of hayes problems lately. Never had problems with my xt's. I sense a shift in popularity of hayes going to saint/xt brakes sometime soon. I hope the new Hayes El Camino will have these issues resolved.

Chris

Have you tried seperating the caliper body yet? Replace the little o-ring in there….could be an easy fix.

Could if be leaking from around one of the pistons? Brakes that old might start leaking around a worn piston….also not that hard to replace. I've got a set of the purple Mags and there really isn't that much to the calipers.

It sounds to me like when the pistons are pushing hard against the rotor, it's making enough pressure to push the fluid out around the piston and would only do it when your on the bike because of your weight….just an idea.

when i rebuilt them in march i replaced the m/c piston, caliper pistons, square seals, caliper halves O ring, bleeder screws, 1 m/c cartridge, both m/c pushrods, both m/c boots, and hoses, pretty much everything except the blocks themselves.

i guess they're just pooched. worn out of tolerance i guess… a lot of abuse in 4 years.

fawk, i'm going to machine a new caliper next week. 6061 billet, monoblock, using hayes OEM pistons and seals…. and i'm going to make it CPS compatable.

so basically i'm going to duplicate the features of the Avid juicy caliper, except using the volume/bore specs of the Hayes Mag caliper.

i'll keep you guys posted.

^ That's gonna be some pimpin shit, man. Custom Hayes caliper? You could start selling all these machined stuff to people.

are those EBC pads any good? and will they work on mechs cuase i was looking into getting some.:)

on the end of the caliper, where the pivot of the lever is, there should be a little plastic cover there. if its not there, then every time you pull on the lever, oil will come out. happened to me on my bighit, i know tape them on so it don't come off. stupid hfx-9 brakes.

i tore down the caliper today, and here is what i found:

-pistons that are like brand new, with the exception of a few small chips on one of them, which aren't anywhere near the square seal (they are actually around the pad spring post).
-square seals with no nicks, tears, or signs of wear.
-caliper halves O ring also no damage at all, except it is a little flatter than it should be. this is where i think the leak is. i also think that the caliper's flexing flattened the o ring over time, causing the leak.

temp solution: face caliper halves to eliminate movement and damage to O ring.

next month: hit up the CNC lab with my autocad drawings, new caliper time!

huck,

shouldn't u just check if the 2 halves are still perfectly flat instead of facing it right away?

wouldn't replacing that o-ring be a simplier solution? o-rings are not meant to last forever.

just commenting.

Calipers flexing causing the o-ring to flatten?

How do you quanitfy how much they "flex"? If they flexed enough that you could notice it, they would be spewing fluid like no tomorrow.

Any chance you rolled one of the seals on re-assembly and that's why its leaking?

I've never heard of caliper flex being an issue on any kind of brake, on both bikes and cars.

try the new seal,watchin people trying to fix stuff that ain't broken is painful