Hayes 9 Adjustment for dummies!

vikingbobw

Hi all,

Just got a Trek Fuel EX 7 with Hayes 9 brakes. Completely new to disc brakes so no jargon if you can. When i gently spin the wheel i get a squeek which, if slow enough will stop the wheel. I dont notice or hear it when riding but was wondering if there is a way to adjust the brakes so this dosen't happen and to adjust the reach of the levers as they are uneven when applied.

Any help or advice for this dummy will be appreciated.

Thanks.

nicklouse

First is the bike new? have you used it? have you bedded the pads in?
do you have a manual for the brakes? download it!

or vist parktools for a how to.

allthegearnoidea

i recently serviced a mates bike with 9's,
if you remove the wheel for easier access and then remove the pads, using a 10mm i think it was allen key gently push the pistons back into the caliper as far as you can, replace pads and wheel, and pump lever, that should sort them out!

as nick said the website has all the downloadable manuals etc for the systems.

the 9's are a pain in the bum for bleeding due to the position of the resevoir and the size of it! almost a top up per pump of the lever!

dave_hill

Hayes 9's do drag a little even when correctly adjusted. As Nick said, make sure that the pads are bedded in properly.

You may also need to adjust the caliper alignment - you can do this easily by loosening the two screws which hold the caliper to the adaptor (or post mounts), then pump the lever a few times. Then hold the brake on and re-tighten the mounting screws.

Pushing the cylinders back in as far as they will go is also a good plot, but take the pads out first.

I use the "bottom up" bleeding method - I attach a large veterinary syringe full of brake fluid to the bleed nipple, take the reservoir cap off, open the bleed nipple and gently pump the syringe to force fluid into the line. Use rags to mop up any spillages and clean fluid off paintwork immediately with brake cleaner.

vikingbobw

How long am i looking at for the brakes to bed in properly?

BlackSpur

Depends - as Nick asked, is the bike new?

vikingbobw

Pretty much if mileage is any indicator. I have ridden it back and forth to work (3M) for a week or so and one ride of 1hr 30 mins on easy terrain.

skyliner

dave_hill wrote:

Hayes 9's do drag a little even when correctly adjusted. As Nick said, make sure that the pads are bedded in properly.

hold the brake on and re-tighten the mounting screws.

That's where the drag comes from.
If you pump the lever a few times as you said, but then centre the rotor between the pads by eye and tighten the PM fixing bolts (can be fiddly and require a couple of attempts), they don't drag and give a more positive lever feel at the bite point.

I'd bet they don't bleed perfectly 1st time bottom up. Bleeding is easier, cleaner and faster if you attatch the syringe at the MC bleed port with the small connector supplied in the bleed kit. Then connect a collection bottle to the bleed nipple and push the fluid through from the top. Then close the nipple, and pump the syringe to force excess air out of the MC reservoir and back into the syringe. At this point, you can also operate the brake to test lever feel and release small amounts of trapped air from the lines(if there is any) for good measure.

I got those tips (and a few more for Hayes) from a Giant Team DH spanner man years ago. And I bleed and service Hayes brakes regularly. I've worked on 3 sets this weekend alone. All bled 1st time with no fuss or mess, and set up with no rotor drag or binding.
Give it a try, you'll be surprised at how easy it is.

dave_hill

skyliner wrote:

I'd bet they don't bleed perfectly 1st time bottom up.

I can only speak from experience, and it does work. I've just done my front this weekend.

vikingbobw

Thanks for the tips. Not having much experience at twiddling it might take me a while to get that done but i will let you know how it went, later.

vikingbobw

Well, got it done after a few attempts so thanks for the tips i'm now onto my other noise, my spokes but thats on a different thread, thanks again.

Milkie

I too have squeky Hayes 9's !!!!

I unbolted the caliper held lever tight and tightened the bolts..

The most annoying thing is, everytime I take out the front wheel, and put it back it bloody squeeks & drags again!?

Surely you shouldnt have to do this everytime you remove the wheel?

TonyS

two pieces of thin cardboard (business card) between the rotor and pad when centering. The 'pump the brake and tighten the bolts' method always seems to leave the pads off center and one in contact with the rotor when I've tried.

After bleeding leaving the bike overnight with the brake lever zip tied on can help firm up the feel - just make sure the lever is vertical.