[Spunger]

Hey guys, I need some help with some hayes brakes, mainly 1 pair, the rear brake.

I have new pads on the back that I put in a while ago, just haven't gotten around to really dealing with the bike yet until now. I have also bled them with NO air in the lines, fluid level out of the brake lever was full to the screw hole.

This is my problem, and it does not change.

IF I push the pistons back into their bores with a box end wrench, install pads, the lever goes to the bars, and like 3-4 pumps later is hard (could consider normal lever feel).

IF I do the business card trick to center to caliper, it works fine, they are centered.

IF I do all this I still have brake rub. The power doesn't seem like my front brake but I bet it needs to be burned in. I can see the pads and they are very very close to the rotor. I'd like the pads to sit where they do when I press the pistons in their bores. They stick out a hair or 2 hairs, especially the one where it says "hayes" on the caliper. It does look dry down there and the only reason I say that is I guess there's an o-ring down there you lube with brake fluid. I have never done that.

SO My question is, is there anyway to adjust how far the pads get to the rotors? I know it has a self adjusting system, but is there anyway to fix this? Any ideas why after being bled 2 times to make sure that they "hayes" side of the caliper retreats itself back? The lever feel is fine, but power to the rotor is definately not seat grabbing like it use to be.

Please help me out and let me know of anything I can try to get the pads to sit where they belong. The front pads aren't that much older than the back pads and they have like 1 1/2 to 2 business card's distance from the rotor when in the rear I am lucky if I can slide 1 card through each side.

Please let me know,
Chris

 

[binary visions]

That was quite a throrough post.

All I have to say is that I have tried all the million and one "tricks" that seem to float around the internet.. Dozens of times.. and the only thing that keeps my brakes from rubbing is if I painstakingly push back the pistons ensuring they are both ALL THE WAY back, then eyeball the caliper to perfectly centered, then tighten down the bolts very carefully so as not to move the caliper at all.

However, after I do all that, my brakes do not rub (except for the occasional "zing" that comes from the weak clips holding the pads on).

As far as one side of the caliper not retreating back.. Are you sure the caliper just isn't off center? I'd say be very careful to make sure the pistons are completely back before you try centering it. I never could get the business card trick to work.

 

[Spunger]

I found this on another hayes thread and it sounds like my problem.

"Wait!!! dont buy a new re-build kit just yet!!!

when you notice the problem of a piston not retracting on any hydraulic disc
try this first...

take the caliper off the bike, take the brake pad of the piston which is NOT
retracting out, get something that you can use to hold back the other piston
(the one with the pad) so need to use something clean and that won't damege the
caliper or the pad (a DH tire lever works great, use the longer flatter end),
while holding the pad back squeeze the lever 3-4 times BE CAREFULL NOT TO PUSH
THE PISTON OUT!!! then push the piston back in and repeat several times. this
procedure helps to move fluid around the piston and lubricate the quad-ring
("o" ring that seals the piston) they tend to dry up sometimes like in hot
weather like you expirienced. just continue to do until both pistons move
equaly.
If that did nothing, then , well you'll need that re-build after all"

Everytime I take my pads off one or both pistions aren't all the way back in their bores, they are out enough probably to cause the rub I am talking about. I need to get those buggers back into their bores and to always retract back into there. Please let me know if this is an ok way to do it or if there are better ways to go about this?

Chris

 

[SKYWAYBUZZ]

They won't go back because there 's too much fluid,I did this last nite puttin in new pads. open the top bleed screw with lever up so hole is at top, then push the pistons in and some fluid will be pushed out the top, I had to really push a couple times to get enough out so the new pads wouldn't rub the rotor, and I left the pads in the caliper and wedged a big screwdriver between them to seperate them both at the same time then snuck the bleed screw back in will holding the pads apart with my other hand so no air.

 

[Spunger]

I am going to give this a try tonight since it is all upside down right now. I will try and see if I can seperate the pads with something or have my girlfriend help me and then go for it. My pistons just don't retract into their bores like the front do so it rubs all kinds.

That is a very good tip, I will try it tonight for sure!

Thanks,
Chris

 

[SKYWAYBUZZ]

I just half burned my new pads in, the pads are close to the rotor but the rear wheel spins great, although; either I want the pads out some more and more lever travel closer to the bar cause now the lever piston isn't moving in enough compared to front, so I guess I'm going to try to pull the lever and then open the bleed screw and let some brake fliud out because the lever must be too full

 

[Spunger]

Well I tinkered around last night and found my problem.

1. O-ring on the screw in the lever was not seating right, and it bsuted off, so now I need a new bleed screw and o-ring.

2. The pistons don't retract all the way like they are suspose to. I tried everything from pushing the pistons back in to re-centering and nothing. They just don't retract that extra few MM like the front do no matter what I do to them.

I am going to have to looking into changing out the piston, its seal, and the tiny o ring as well I guess, re-bleed and give it another shot.

ANY other ideas?

Chris

 

[SKYWAYBUZZ]

My bleed sctew is screwed to, it goes in then spins, but no oil has come out yet.

 

[Repack]

Originally posted by SKYWAYBUZZ
They won't go back because there 's too much fluid,I did this last nite puttin in new pads. open the top bleed screw with lever up so hole is at top, then push the pistons in and some fluid will be pushed out the top, I had to really push a couple times to get enough out so the new pads wouldn't rub the rotor, and I left the pads in the caliper and wedged a big screwdriver between them to seperate them both at the same time then snuck the bleed screw back in will holding the pads apart with my other hand so no air.

My thoughts as well. I would use a credit card (or similar) to hold the pistons all the way in, with the pads installed. I don't like business cards cuz they compress. Then slowly back out the screw. A few drops of oil will leak out.

 

[Spunger]

Well I got a new screw for the lever. I got a couple of them.

I tried pushing the pistons back in. I did notice some air comming out when bleeding but I think I got all the air out. I went through most of the little bottle of hayes fluid. I am almost positive that all the air is out.

This is what happens. Tell me if this sounds right or not. After bleeding, and centering the lever, and doing the credit card trick, the lever will go to the bars, and after 3-6 pumps it will return to normal feel. It just doesn't have the "grab" that the front one does. My front brake would throw me off. The back one will barely squeek the tire to skid. I check the pads and they have a light black glaze to them. I took my dremel tool and lightly sanded the top layer off. I cleaned the rotor with alchie and still same thing.

The funny thing is I was pulling the lever and it went all the way to the bars for a lil while and then seemed to stiffen up. I am going to take it on a ride today to see if it changes any. I checked the front pads and they look like they are half worn down, new ones in the rear maybe have 1/8th of the orignal pad worn off. I kind of like them not "skidding" because it gives the illusion of riding the brake but I'd like them to atleast stop when I really grab them. Maybe they need to be burned in some more, I should go try that next since I feel they are bled as much as I can bleed them.

I don't expect them to be super quiet. The rear has a quick release which I know will always change. Maybe I just need to tweek things some more but jeez, if I would have known how good they work when they work, I'd take them anytime, but if i knew how the maintence is on them well.........I might have second considered. It's not time consuming stuff so that is good, takes only a few minutes to bleed, pad changes are easy, so I guess I can't complain too much.

Let me know if all this sounds normal?

Chris

 

[gonzostrike]

1) let some fluid escape

2) use the shim that Hayes provides, it's thicker than a credit card, about 2.5 credit cards thick.

3) squeeze lever, refill, bleed.

4) properly align caliper on its mount

ready to go

 

[LowTensileHuffy]

This is what I do all the time, sorry if i'm describing this for no reason. If your lever is going to the bar every once in a while, its sounds like you definetly have air in there. Make sure when your bleeding that the hose coming out of the caliper is straight uphill, ( I usually let the caliper hang off of the bike) try to have the hose all uphill as well. while bleeding use a wrench to push on pistons a couple of times each and tap on hose as well as pumping lever slowly, watch for sharp bends in hose and obviously kinks. I don't know if you have a stand but it makes it much easier. And if you've got six arms it can be done in less than 30 seconds, having never seen that I can't be certain.