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Adjusting Hayes Hydraulic Disk Brakes

20578 Views 11 Replies 8 Participants Last post by skywaybuzz, Aug 27, 2004

pcrap

Discussion Starter · Aug 2, 2004

Hello all,
I have Hayes HFX-9 HD hydraulic disc brakes - my first pair of hydraulic disks. I still can't seem to keep the pads from rubbing on the front rotor. I've tried all the tricks I know to adjust the brakes: 1) remove the caliper and pads, separate the pistons with a 10mm box end wrench, re-install the pads, re-install the caliper and mounting bolts and tighten them while I squeeze the brake lever, 2) put business cards between the rotor and pads and tighten the caliper mounting bolts, 3) bleed some brake fluid in case it was overfilled during assembly, 4) check that the front wheel is straight in the fork, and 5) simply the "loosen-adjust-tighten" trial and error approach. Still the pads rub- it seems as though there isn't enough clearance between the pads for the rotor to spin without some drag. If I could only get a little more clearance between the pads I'd be OK. Any help or suggestions??
Thanks

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jagayers

· #2 · Aug 2, 2004

pcrap said:
Hello all,
I have Hayes HFX-9 HD hydraulic disc brakes - my first pair of hydraulic disks. I still can't seem to keep the pads from rubbing on the front rotor. I've tried all the tricks I know to adjust the brakes: 1) remove the caliper and pads, separate the pistons with a 10mm box end wrench, re-install the pads, re-install the caliper and mounting bolts and tighten them while I squeeze the brake lever, 2) put business cards between the rotor and pads and tighten the caliper mounting bolts, 3) bleed some brake fluid in case it was overfilled during assembly, 4) check that the front wheel is straight in the fork, and 5) simply the "loosen-adjust-tighten" trial and error approach. Still the pads rub- it seems as though there isn't enough clearance between the pads for the rotor to spin without some drag. If I could only get a little more clearance between the pads I'd be OK. Any help or suggestions??
Thanks

I have the XC model and am having the same trouble with my front brake. On mine, it looks like the inside piston isn't retracting all the way. I posted a similar thread a week ago and I was told to keep pushing the piston back and forth untill it works free and retracts, or spray windex into the piston. I didn't try the windex trick, but I am not sure if it is a good thing to do since all I have read about brakes tells you to only use alcohol and alcohol only. I plan on doing a good cleaning with alcohol before this weekend ride and see if working the pistons back and forth does anything.

Let me know if you find a solution. Right now, I have a little drag, but I can ride with it. By the way, do you also have to use the Mounting Adapters for IS mounts?

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pcrap

Discussion Starter · #3 · Aug 3, 2004 (Edited)

It took a while, but I think I got it!! Just needed a more time and effort (and luck). I had just said, "good enough" when I tightened the upper bolt and the wheel spun silently!

Here is what worked for me:
Loosen the caliper mounting bolts, squeeze the brake lever, tighten the mounting bolts. If you are lucky, apparently this is all it takes. If you are unlucky (me), this will get you in the ballpark. Then it is a matter of loosening/tightening the mounting bolts to adjust the caliper position. I found it worked well to keep the lower bolt somewhat tight, and make small adjustments while loosening/tightening the upper bolt. Unfortunately, tightening the mounting bolts produces small (annoying) changes in caliper position. Also, having the bike off the ground is a must - so you can easily check for pad drag.

I hope it stays dialed in, 'cause it was a pain in the butt!

Also, I have 8" rotors and I use the necessary adapter since my frame has standard mounts.

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vermont

· #4 · Aug 4, 2004

jagayers said:
I have the XC model and am having the same trouble with my front brake. On mine, it looks like the inside piston isn't retracting all the way. I posted a similar thread a week ago and I was told to keep pushing the piston back and forth untill it works free and retracts, or spray windex into the piston. I didn't try the windex trick, but I am not sure if it is a good thing to do since all I have read about brakes tells you to only use alcohol and alcohol only. I plan on doing a good cleaning with alcohol before this weekend ride and see if working the pistons back and forth does anything.

Let me know if you find a solution. Right now, I have a little drag, but I can ride with it. By the way, do you also have to use the Mounting Adapters for IS mounts?

i have been having the same problem with the piston not retracting fully...i put some judy butter on it and it has worked okay ever since...still not perfect but its not rubbing the rotor now. Keep this thread posted on what has worked for you if you have encountered this problem....Also be very careful pushing the pistons back...they can get dry and crumbly i've heard of guys cracken em tryin to push em back...

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Skettio

· #5 · Aug 6, 2004

Here's the trick

Loosen both bolts on the caliper mount. Not a lot but just enough so the caliper can move slightly. Now, squeeze your lever tightly. You should see the caliper move to center itself on the rotor. All you have to do now is move the caliper side to side (left to right when looking down at the fork) a few times. After wiggling a few times let the caliper come to a natural resting position, then release the lever. Do that procedure one more time, except hold the lever while you tighten the bolts. This should do the trick. Always check your rotor for trueness, sometimes a little bending can take care of the little schings you hear.

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SeamusCA

· #6 · Aug 11, 2004

Similar problem, but different

I've got a new IH Hollowpoint with Hayes hydraulics, and the caliper seems to mount too far 'inside'. IOW, the left side of the caliper actually rubs the disk. I have tried various loosen-tighten things, but it doesn't seem to be helping. If the right side was too close, I could shim the caliper mount with thin washers to move it slightly in, but I've got the opposite problem. I don't really want to start removing material from the caliper or fork. What about a washer on the front axle? It seems that would mess up the geometry, as the wheel would no longer be centered in the fork.

Any suggestions?

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vermont

· #7 · Aug 11, 2004

can you post a picture of this there has to be a solution for you.

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SeamusCA

· #8 · Aug 12, 2004

vermont said:
can you post a picture of this there has to be a solution for you.

I'll post one tonight. Thanks for the response.

Jim

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Wombat

· #9 · Aug 13, 2004

SeamusCA said:
I've got a new IH Hollowpoint with Hayes hydraulics, and the caliper seems to mount too far 'inside'. IOW, the left side of the caliper actually rubs the disk. I have tried various loosen-tighten things, but it doesn't seem to be helping. If the right side was too close, I could shim the caliper mount with thin washers to move it slightly in, but I've got the opposite problem. I don't really want to start removing material from the caliper or fork. What about a washer on the front axle? It seems that would mess up the geometry, as the wheel would no longer be centered in the fork.

Any suggestions?

The shim on the front axle will work, and there is really nothing to mess up on your front geometry as shims around .05 mm will make a big difference. To make sure that the axle still "bites" into your forks it's worthwhile placing the sim inside the outside washer on the axle. My XT hubs have such a shim as standard.

Wombat

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SeamusCA

· #10 · Aug 14, 2004

Doh!

After further examination of the caliper mount, I discovered two additional hex screws mounting the caliper to the caliper mount. There is some wiggle room designed into these mounts, and loosening, centering and tightening took care of the drag.

Be gentle. It's my first bike with disks (Hayes HF9).

Jim

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SpinWheelz

· #11 · Aug 27, 2004

I have a new bike and I'm already having issues with the front brake dragging. Did a search and found this thread. I've tried some of the methods listed here, but to no avail. My problem is virtually identical to those described here: the inside pad is rubbing against the front rotor. The Hayes caliper I have is mounted onto a bracket that is in turn mounted onto a a Cannondale Lefty Max fork.

When the instructions say tighten the mounting bolts, does this refer to the mounting bolts that connect the caliper to the bracket or the bracket to the fork itself? Or both? I've found that when I tighten the bolts that connect the bracket to the fork, the rub becomes greatly exaggerated, almost to the point that there's a clunking noise from the rotors when the wheel spins. So I have to loosen those bolts up but that makes me nervous riding around without brakes tightly bolted to the fork.

Here's something I'm trying to figure out. I have two sets of ultra-thin washers that go between the fork and the mounting bracket. There are 4 on top, 3 at the bottom... or the other way 'round, I can't remember. In any case. It feels like I might benefit from more washers there, in order to 'push' the caliper inward toward the hub so that the inside pad can clear the rotor. Is this an option or am I going down a path that'll complicate setup in the future?

I've already read somewhere that this rub is to be expected in new brakes? Is that true? If so, am I fidgeting around with the brakes needlessly at this point?

Any other Lefty owners out there with these Hayes HFX-9 hydros with recos?

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skywaybuzz

· #12 · Aug 27, 2004

just the caliper not the adapterbolts, you could add more thin washers to the adapter to move it out. Are your pistons the same distance out when you pull the pads out-check- maybe the inner one is out to far, if so just push it back, and you don't need them oval washers on the caliper bolts if your having trouble with them moving the caliper when you snug the caliper bolts down. A good bike shop will have the thin washers, you can get em real thin orthicker. Reg small washers also work instead of a million thin ones, then fine tune with the thin ones. You can also round file the caliper mounting holes a little to get the position you want,but then you will not want to use them oval washers on the caliper bolts unless you modify them aswell smaller. I've dione this with mag hayes brakes never worked on the HFx-9. Yes new pads will rub possibly until they wear flatter

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