Adjusting the rear brakes

Ok, here's the deal. I put a new rear tire on my 01 WR426 and now when I use the rear brakes they aren't doing anything. This wasn't a problem before I swapped the tire. I looked in my book (which sucks) and I've tried to research it on Google with no luck. In looking over the rear brakes/rotor I grabbed the rear brakes and they have a little bit of slop (slightly move back and forth) on the rotor.

1. Should there be this slack between the pad and the rotor?

2. How do I tighten this slack and properly adjust the brakes?

A little bit of slop is ok. Does your brakes lever travel through its full sweep and not stop the wheel at all?

Is your caliper properly mounted?

Did anything weird happen during your wheel removal/refit?

Is the brake lever hard/have no movement?

Sorry, dumb question - is there any fluid in there?

The brake lever goes all the way down and does nothing. Nothing was changed on the caliper (I had a bike shop put the tire on for me).

Nothing weird happened when I took it off or put it on. As far as the flud...I "assumed" since I didn't have one drop leak it would be fine as it was before.

Hi HamBone, sound's like a dirty brake disk ( rotor ), simple as a few dirty finger prints, a spot of grease from the wheel bearing, and the kind of general handling a wheel get's, when you change the tire.

First off, double check the mechanical installation of the wheel, if your not sure get a second oppion.Then try cleaning the disk with a brake/clutch cleaning spray.

Once you have oil on the disk ,it get's on the pad's and the

foot peddle feels ok , but the brake only works 15% efficient.

Hope this helps



OK, you removed the wheel and took it to the shop for a tyre change right?

How many times have you pushed the lever through its stroke since the wheel went back on; if its only once or twice then keep on doing it, as its likely the pads were pushed back during wheel jiggling to get it out/back in.

Or, freak occurance and brake needs bleeding :)

That thing in the reservoir is part of the cap assembly and is supposed to be there.

Judging by the colour of the fluid I can see, it wouldn't hurt to change the fluid anyways. :)

Yes, I removed the wheel and took it to the shop.

I took the bike for one test ride down the runway (it's an asphault taxiway for airplanes) and then came home. I started it yesterday but only drove around the house twice.

I just took the lid off and didn't realize the black insert went down so far. The fluid is red and looks to be in pretty good shape. I didn't really have anything to clean off the rotor so I just used some carb cleaner and gave the rotor a quick spray around it. It's working a tad bit better. Unfortunately the neighbors kid is napping so I can't fire it up and try it out yet, I have a Big Gun on it and all the neighbors know it!!!

Carb cleaner will do just fine, or some fuel from your tank :)

Let's hope it's just muck and reseating of pads :)

I have a race ackro system on my 450 and yeah, the neighbours love me too!!

Should I take the pads off and give them a shot or should I just ride it (safely) :) until the pads catch and work again?

Pop 'em out and check to see if they're clean and dry, can't hurt...

Deglaze them while you're there, doesn't take two minutes. A sheet of medium sandpaper flat on a worktop and rub each pad on it until the 'shine' is gone from the surface. Don't go mad! only takes a few reps. :)

Ride the bike, if the feel of the brake is no better after half an hour, let's get the pad's out and have a look. ( safely ) is the key word here.

Most of us keep the back brake covered all the time, but rarely use it.

Just sometime's it's the only thing that can put balance & control into a given situation.

When i clean my Chane (wash my bike ) , if i get contamination on the rear brake disk, it can take several day's before the brake gets back to normal.


What kind of contamination are you referring to from when you wash your bike? Are you referring to a pressure washer and blasting debis on your rotor?

No pressure washer, but wash the bike by hand, often the rear caliper gets soaked with water ( the pads soak this up like a sponge ) and it needs time to dry out.

Or if i have given the Chane a really good de-grease & clean, the rear rotor can get covered in all sorts of crud. Often the inside of the disk ,facing the hub , where we can't see and dont clean too often.

Contamination is a general term, if the brake system is not 100% clean & dry it will

be suffering from contamination of some sorts.

Hope this helps, got to go to bed now, will check the thread manana.

PS. Sorry about the Grand Prix , what a load of cr*p.

The french ( team renault ) must be keeping a low profile now.

You yanks were rightly pissed off.


Cool...thanks so much for the input you all have given. I'll give it a shot and try the bike out again. :)

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