rear brake gripping apriliars250

[nudedaytona]

I have an aprilia rs250. The rear brake is gripping the disc, and it sounds like the pads are worn (brembos brakes). Can someone please tell me what I should do to fix it?

[Kwaka14]

Pull the pads out, pump the pistons out a small amount and clean them thoroughly, push them back, reassemble and flush out your old fluid with new and bleed them properly should do the job.

[imdying]

Yep, what he said. To clean them, use hot soapy water and a tooth brush.

Also make sure the the push rod for the rear master cylinder has a little free play, that you can jiggle it... if it is under tension all the time, it'll hold the rear brake on, and that's no good :no:

[imdying]

Oh, do your front caliper pistons too... amazing the difference at the lever with nice shiny pistons... clean them every 2-3000kms and they'll always treat you well :)

[nudedaytona]

Also make sure the the push rod for the rear master cylinder has a little free play, that you can jiggle it... if it is under tension all the time, it'll hold the rear brake on, and that's no good :no:

What's the push rod for the rear cylinder?

[nodrog]

What's the push rod for the rear cylinder?

please take your bike to a shop, or at least get sombody competent to give you a hand. I'm not trying to be a cunt, it just sounds like from some of your posts you dont have much mechnical knowledge, and brakes arent the sort of thing you should fuck around with if you dont know what you are doing.

goodluck, if i was up in your area i would give you a hand.

[nudedaytona]

please take your bike to a shop, or at least get sombody competent to give you a hand. I'm not trying to be a cunt, it just sounds like from some of your posts you dont have much mechnical knowledge, and brakes arent the sort of thing you should fuck around with if you dont know what you are doing.

goodluck, if i was up in your area i would give you a hand.

Thanks for the offer. I've replaced and bled disc brakes in the car a few times, so I don't see why a bike should be so difficult. So I don't know what a push rod is, big deal. How about you tell me what it is and let me worry about whether my bike is safe to ride, or whether I'll fix it or get someone else to.

[Crisis management]

Don't take Nodrog the wrong way, he's just trying to make sure you don't accidentally fuck yourself up. It's one of the dangers of advice on the net.....

Imdying is talking about (I think) the rear master cylinder. It is not uncommon for the brake lever to be adjusted in such a way that there is no free play left on the pushrod to the master cylinder leaving the brakes always applied slightly. Check the freeplay so that doesn't happen.

Enjoy the playing!

[SimJen]

I have an aprilia rs250. The rear brake is gripping the disc

S'funny, thats what I thought brakes were supposed to do?
You'll always get some drag with disc brakes.
Anyway its a good time to give them a clean up, clean the pistons and change the fluid, makes all the difference.

[nodrog]

So I don't know what a push rod is, big deal. How about you tell me what it is and let me worry about whether my bike is safe to ride, or whether I'll fix it or get someone else to.




Imdying is talking about (I think) the rear master cylinder. It is not uncommon for the brake lever to be adjusted in such a way that there is no free play left on the pushrod to the master cylinder leaving the brakes always applied slightly. Check the freeplay so that doesn't happen.

Enjoy the playing!


yes the push rod is on the master cylinder, and with the brembo ones it is easy enough if you dont know what you are doing to adjust it up too far, you need to allow for the expansion of the fluid, otherwise when it gets hot it will bind on and fuck your caliper, pistons, and brake disc, trust me i found out the hard and expensive way.

[imdying]

What's the push rod for the rear cylinder?Heh, you worry me mate :lol:

On the right hand rearset (the thing that has the peg on it), you'll find the rear brake master cylinder. Between that and the lever that your foot pushes down on, there is a push rod. That must have a little bit of free play in it, or it'll make the brakes drag.


First thing you should do on any bike is adjust all the levers and switch gear to suit your body side and riding position... that includes the span adjusters on the clutch and brake cylinders, and the height of the gear shit lever.

If you ask nicely, someone on here will be sure to help you :) I'm not much good to you, I'm in Christchurch. If you post pics though, I'll help where I can. Brakes probably shouldn't be your first port of call though for learning how to spanner :D

[imdying]

Righty ho then!

See figure 1.
- Caliper needs to be unbolted from the bracket labeled 7
- Take the pads out, that thing on the bottom left looks like it, probably just an R clip holding them in. Use your common sense, it'll be easy to find
- Put something between the pads, something soft like wood, and about 4-6mm thick.
- Pump the pistons out, evenly. Take note if one is reluctant, that one requires extra love.
- You'll see that the portion of the piston that is exposed wil be dirty, and the bit that has been living inside the caliper is shiny. Scrub the pistons with hot soapy water till they're shiny all over.
- Push the pistons back in, and reverse the disassembly steps.
- Bolt the caliper back on, pump the foot brake lever until the pistons have come back out.

Now, if when you pump the pistons out, no shiny portion becomes exposed, you'll need to remove the caliper so that you can strip and clean it properly. You'll also need to buy some caliper seals (the inner ones, just reuse the dust seals). Any good brake specialist can help you with those.



Picture 2, see the threaded bit that part number 3 goes on to? That's the rear brake master cylinder pushrod. You should be able to jiggle it a little (i.e. it's not bound up all the time).


Have fun, and don't stress if you pump a piston out too far and it starts pissing fluid everywhere. You haven't broken it, you just need to push the piston back in and rebleed the system. If you need to push the piston back in, make sure you get it square. It'll need a medium force to get it back in, not too much though, it shouldn't be too hard to get in.

[nudedaytona]

Picture 2, see the threaded bit that part number 3 goes on to? That's the rear brake master cylinder pushrod. You should be able to jiggle it a little (i.e. it's not bound up all the time).

If I can't jiggle it - what should I do?

[imdying]

Get a second opinion :yes: I'd do it myself, but I'm in Christchurch. Your idea of jiggle and mine might be different :D

That adjuster lets you move the pedal up and down... in theory, it can't be misadjusted to that it binds, but it should still have a little slop in it so that the read brake doesn't drag.

The rear brake lever, when you wiggle it up and down with your foot... is there enough slop in the system so that the pushrod doesn't start to push the brakes on slightly?

[FROSTY]

I have an aprilia rs250. The rear brake is gripping the disc, and it sounds like the pads are worn (brembos brakes). Can someone please tell me what I should do to fix it?
Bring the bike to me and I'll have a look for ya
Although in theory you are working with pretty simple hydraulics theres a few things can catch you out.
As others have suggested FIRST time you play with brakes on a bike have an experienced person watching

[nudedaytona]

Thanks for all the help here. I have replaced pads, which went fine, bled brakes. But the pads are still rubbing on the disc. The brakes not on, the wheel moves easily enough.

I've tried fiddling around with the push rod. I think the problem is that I haven't been able to unscrew it far away enough from the cylinder. Every time I try it feels like it the male bolt is going to come away from the female part. Maybe the disc has a wobble in it?

Anyway, I'm going to take it to a workshop and get an expert to have a look at it. Despite the lack of success here, it is my opinion that it is always better to have a go at things yourself before taking it to the shop, at least you learn more about the bike that way. I haven't made it worse than it already is, and I think I would have to be extremely unlucky to totally f*l things up.

[Devil]

But the pads are still rubbing on the disc. The brakes not on, the wheel moves easily enough.

If the wheel is moving fine, there is no problem. It's the disc that pushes the pads back, they'll always be brushing the rotor gently. ALWAYS.

[Chad]

I'm havin a similar problem on my CBR250R, I know that with discs theres usually a little drag as the pads are always in contact with the disc, but rear brake is def stuck on too hard. I'm new to bike mechanics aswell, but would it be pretty much same deal to sort mine?