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Stuck rear brake

Posted: Sat Jun 30, 2007 9:19 pm
by Hagar
HEEEEEELP

Mrs Hagars Gagiva V Raptor doesnot have a working rear brake and she has told me to fix it :??? :??? Now as some of you will know I know as much about bike mechanics as I do about quantum physics or brain surgery which is zilch. So the problem is this; there is fluid in the reservoir, no leaks (as I was travelling behind her today)but the brake would appear to be binding. there is a lot of movement in the pedal (50 mm at least) but the brake light does not come on. How do I go about fixing it :confused Is it mearly a case of adjusting the control rod or what should I be doing. All help will be greatfully received.

Hagar.

Re: Stuck rear brake

Posted: Sat Jun 30, 2007 9:23 pm
by memini
take the caliper off and check how much of the brake pads are left if hardly any of the pad .change them and try brake if still not working looks like you shall have to bleed it

Posted: Sun Jul 01, 2007 12:24 am
by Gazza
If you know nothing about mechanics then surely you're in the same league as Mrs Hagar.

Get her to fix her own brake. :2up

Posted: Sun Jul 01, 2007 1:42 am
by Hagar
Gazza wrote:If you know nothing about mechanics then surely you're in the same league as Mrs Hagar.

Get her to fix her own brake. :2up
Yes we are both in the same league but she thinks that since she is in charge of the kitchen and I am in charge of the garage that I should be able to fix her bike so helpfull pointers from my fellow bikers I thought would be a simple thing to ask for, but obviosly from your reply it is not.

Posted: Sun Jul 01, 2007 8:37 am
by al
Go out and get yourself a small bottle of DOT4 brake fluid and a tub of cotton buds (have some kitchen towel handy incase of spills).

Suss out how to remove the calliper from its mounting but leave it conencted to the hose.

Next remove the pads. Inspect pads an make sure there is a good amount of friction material on them . If not, replace.

At this point it will be obvious how many pistons the calliper has. Single pot will have one, twin put will have two, most likely one on each side.

What do so now is gently squeeze the brake peddle whilst watching the pistons. What you want to do is, working from one side at a time with twin pots, extend the piston a few mm out from the body of the calliper so that you can see the clean shiny material. Do NOT allow the pistons to come out too far and pup out or they will be a bugger to replace and you will end up with fluid everywhere.

Take a cotton bud and dip it in some of the clean brake fluid. Jently clean the outer body of the piston i.e. the face that contacts with the calliper body. Change cotton buds regulary so that you remove all the crap. Try to take strokes from the shiny clean part of the pison body out to the end of it so that you are wiping the dirt away from the seal.

Once the body of the piston is clean you should be able to gently push it back in to the body of the calliper using your fingers. If the calliper has more than one piston then try and not let the other piston move when you are pushing the cleaned on back in.

If you didn't clean the other piston at the same time then clean it using a similar method.

By the end of it, all the pistons should slide in and out fairly freely.

If all goes well the brake should be working properly again. If so you might want to do the same with the from callipers as a preventative measure.

I try and clean my callipers using this method at least twice a year and I haven't had any problems with mine!

Big Kneed Al (master of the emergency stop & "stand up" comedian).

Posted: Sun Jul 01, 2007 9:12 am
by Gazza
Hagar wrote:
Yes we are both in the same league but she thinks that since she is in charge of the kitchen and I am in charge of the garage that I should be able to fix her bike so helpfull pointers from my fellow bikers I thought would be a simple thing to ask for, but obviosly from your reply it is not.
Why not wheel the bike into the kitchen? ;)

Posted: Sun Jul 01, 2007 10:22 am
by speedaddictedberk
Is there good pressure at the brake lever? It might help if you replace the brake fluid as well, then bleed the system.

I'd use brake cleaner and an old toothbrush to clean the pistons instead of brake fluid (it's easier to clean up).

Posted: Sun Jul 01, 2007 10:35 am
by al
speedaddictedberk wrote:Is there good pressure at the brake lever? It might help if you replace the brake fluid as well, then bleed the system.

I'd use brake cleaner and an old toothbrush to clean the pistons instead of brake fluid (it's easier to clean up).
The brake cleaner is good ar removing and washing away all the loose crap before you start with the brake fluid but I wouldn't use a toothbrush. Brake cleaner won't remove all the lumpd of crap that seem to bind to the pistons. However if you are patient with the cotton buds and brake fluit you can remove all the crap from the piston with gentle rubbing thus leaving the sirface intact.

Sticky pistons can give the feel of spongey brakes so watch out for that. I've seen folk who have had spongy brakes fork out a load of £££ for braided lines and to still have spongey brakes because they didn't find the root of the problem in the first place.

If your brake fluid is a nice light colour then it should be ok. If it starting to turn dark coloured then it needs replaced.

Big Kneed Al (master of the emergency stop & "stand up" comedian).

Posted: Sun Jul 01, 2007 10:37 am
by al
If your brakes are binding ( wheel hard to turn by hand or the bike noticible hard to push) then it will be the pistons. It will need sorted before you end up warping your disks!

Posted: Sun Jul 01, 2007 12:26 pm
by Hagar
Thanks for all the replies, I will give it a go and see how I get on.

Posted: Sun Jul 01, 2007 12:32 pm
by tintin
Hagar before you do anything, remember that brake fluid is nasty stuff that will ruin paintwork. Get plenty rags and 'mask' anything you'd like to keep the original colour :eek

You can usually remove the pads without taking the caliper off the bike or disconnecting any hoses although maintenance is easier with the caliper off the bike but still connected to the brake line (just be sure you disconnect the correct bolts and torque them correctly when re-assembling). You may have to remove a dust cover on the caliper and then a pin(s) to get the pads out. The pin will be held in place by an 'R' clip or similar and taking this off will let the pin slide out.

With the pads out and the caliper off (still connected), don't press the brake or the piston(s) may pop out, spraying fluid everywhere. The easy way to free/limit their movement is to prepare wooden spacers which you can use to limit their travel. If you have a multiple piston arrangement and one piston is stuck, you can use these spacers to 'lock' the working piston and a thinner one to make sure that when it does move, it won't fall out. Once set up like this, providing the fluid system is ok, pressing the brake will put all the farce onto the seized piston. Once it's moved you can clean it as Big Kneed Al (master of the emergency stop & "stand up" comedian) suggests.

If only one side is seized, push the 'good' piston all the way in and put a spacer in the caliper and another on the outside and use a 'G' clamp to lock it in place.

I'm no bike mechanic either but I found this by trial and error when sorting Lynners bike. I'm heading for englandville this afternoon for the week but if you're still needing a (non expert) hand next weekend give me a shout and I'll try and help.

Good luck

Posted: Sun Jul 01, 2007 4:12 pm
by al
One thing to watch for when you push the pistons in is that you keep an eye on the brake fluid reservoir. The level will rise in the reservoir and depending on how worn your pads were and if you push the pistons all the way in the excess fluid may try to escape from and drip on your paintwork! :nono

Posted: Mon Jul 02, 2007 8:56 am
by rasmie
This would be a good subject to save somewhere. All of us need great tips like this at some point no matter how long we've had bikes.

Posted: Mon Jul 02, 2007 9:22 am
by shortassrider
im not a mechanic either but i noticed nobody mentioned the cable ?.
if there is so much play ,could there mabe be a problem their also ?. worth a look i think . anyone any reply on this. :confused

Posted: Mon Jul 02, 2007 9:34 am
by yelloisfriedegg
shortassrider wrote:im not a mechanic either but i noticed nobody mentioned the cable ?.

:roll







actually it's quite scary that you are allowed to ride a bike and make comments like that :(

Posted: Mon Jul 02, 2007 9:36 am
by shortassrider
lmao sorry , back brake . told you i was no mechanic :oops :oops :oops

Posted: Mon Jul 02, 2007 9:41 am
by yelloisfriedegg
shortassrider wrote:lmao sorry , back break . told you i was no mechanic :oops :oops :oops
even more scary now :roll

Posted: Mon Jul 02, 2007 9:44 am
by shortassrider
yelloisfriedegg wrote:
shortassrider wrote:lmao sorry , back break . told you i was no mechanic :oops :oops :oops
even more scary now :roll
em your losing me :roll

Posted: Mon Jul 02, 2007 9:50 am
by yelloisfriedegg
I thought I would share this pm :

Inbox :: Message
From: shortassrider
To: yelloisfriedegg
Posted: Mon Jul 02, 2007 9:47 am
Subject: break
i thought it was a push bike , honest I can't believe it's not butter!


:roll

Posted: Mon Jul 02, 2007 9:59 am
by shortassrider
ohh getting a bit smart arse bitchy now are we :tung

Posted: Mon Jul 02, 2007 10:18 am
by yelloisfriedegg
shortassrider wrote:ohh getting a bit smart arse bitchy now are we :tung
nope..........



....thick as mince are we ? :roll

Posted: Mon Jul 02, 2007 10:32 am
by shortassrider
dunno , are you ?

Posted: Mon Jul 02, 2007 10:52 am
by RK6
shortassrider wrote:dunno , are you ?
Now now, come on!

Whats the deal here?

You made a stupid comment and are now defending it with insults :nono

Gonnie no dae that :???

Posted: Mon Jul 02, 2007 11:39 am
by al
This is a motorcycle site so unless stated otherwise it is usually safe to assume that questions posted on the site are motorcycle related.

Big Kneed Al (master of the emergency stop & "stand up" comedian).

Re: Stuck rear brake

Posted: Mon Jul 02, 2007 11:46 am
by yelloisfriedegg
Hagar wrote:HEEEEEELP

Mrs Hagars Cagiva V Raptor does not have a working rear brake
all the clues anyone could need to know hagar is not referring to a pushbike are right there if you look closely , hell , even if you don't look close at all there's not much doubt really :roll


............and he can also spell "brake" unlike a certain poster :I can't believe it's not butter!