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Hayes HFX9 Pad and rotor replacement

Jon Kerr

Chimp
Jan 30, 2008
36
0
San Diego, Ca.
OK guys. I need help. I've never worked on disk brakes before. I'm replacing the pads and rotors on my Hayes brakes. (Pads are pretty bad and the rotors are wore a bit too and slightly warped) The problem I'm having is that the new pads are so thick, there's no way a new rotor is going to fit between them. I've followed the instructions to a T. I've pressed the pistons back into the caliper as far as they'll go (the outside rim of the piston is flush with the body of the caliper.) The pads are in the right way, But there's just too much material there to allow the rotor to go between them. I've mic'd everything. The new pads are 4.0mm thick, old ones were 3.55mm. And the new rotor (Hayes V6 replacement rotor) is 2.00mm and the old one is worn to 1.6mm. Did I get the wrong rotor? What am I doing wrong?! :imstupid::bonk:
 
Aug 6, 2006
351
0
Denver, CO
chances are, your brake will need bled too. Everytime I've installed new pads in my hayes nines, pushed the pistons back, they wouldn't stay back. Bleeding air out of the lines, and sometimes rebuilding the caliper/cylinder would be require to fix this. Even after these steps have been taken, there should be minimal drag noticed with the bike in the stand. A break in period of 30-40 hard stops is required to burnish in the new pads and rotor. If you are just replacing the pads, the time is usually less.
 
sound like a good oppourtunity for you to learn your brakes, if you want to dig into them and get and education you will need to buy some brake fluid, a bleed kit and some rags to cover your parts.

otherwise you can take it to a local bike shop and get raped financially and not get a good bleed back with your bike, lol

the deal is simple with your hayes, since you are cramming two new bigger parts into a caliper that is used to a smaller set of parts you need to start from scratch. crack open the resi, install the new pads and squeeze them over the rotor. mount it all up and then re bleed your system, once they are bled you can squeeze the lever and they will adjust.

the other option is to take of the hayes all together and trade them for formulas or saints, but that is my opinion.

dont get brake fluid on your paint by the way, thats what the rags are for. and keep the fluid away from your rotors and pads. I usually will hit any rotor I take off a bike with brake cleaner and you can use windex to clean frame parts that have been contaminated with brake fluid.

good luck
 

zebrahum

Monkey
Jun 22, 2005
406
0
SL,UT
Try pushing the pistons back with the lever body bleed valve open. It'll loose some fluid, but should keep the pistons back.

No matter what, you're likely to have some rubbing when you put new pads and new rotors together, you need to heat those babies up with some hard stops to get the rotors burnished and the pads to a better tolerance.
 

Jon Kerr

Chimp
Jan 30, 2008
36
0
San Diego, Ca.
Thanks for the advice guys. I was pretty sure I was going to have some rubbing when I realized it was time for some maintenance. That much was obvious. But I wasn't expecting almost locked up rubbing. :poster_oops: I'll pick up a bleed kit tomorrow. That's something I need to learn anyways. It's tough for me to be so behind on technical knowledge. My other hobby is racing R/C Cars at a pretty highly competitive level. I'm a sponsored racer and I'm pretty good with setups and detail work on building and tuning cars. So being a noob again isn't a comfortable feeling. :banghead: It's nice to get advice like this and not be talked to like I'm an idiot.
 

jezza169

Chimp
Aug 14, 2009
1
0
I have a stinky with the HFX9's, it could be that you just need to sand down the pads until the rotors fit? Are the pads aftermarket? Up until i found the pads cheap at DiscoBrakes, i would have to wear down the pads a little to get thm to fit!!! saves you some time, and some money!!! I might be wrong this time, but just keep that in mind for when you change your pads next!!!!! :) will save you having to rebleed the system!!!!! I love these brakes!!! :)
 
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