I think my back brake is sticking?

satanicguardian · 16 Jan 2015 at 15:49

Hi guys,

Slight issue with my bike, I've noticed it in the last few weeks since it's been really cold/gritters out; my brakes started to get squeaky (front and back) and sometimes feel a bit spongy.

Recently though I've noticed that when I try and get my bike out of the garage in the morning, I try and wheel it back whilst sitting on it, at certain points it will be really hard to push back (as if a certain part of the disk is sticking or something?) then will roll freely again for a few feet until that part of the disc comes back round to the caliper

I'm borrowing a paddock stand over the weekend to get the back end up in the air, I'm fairly novice to servicing, but is there anything I should look out for?

Cheers

wazza300 · 16 Jan 2015 at 15:59

rotate the wheel to see where its rubbing,id also check your chain for tight spots,it could be that

you want a g clamp and take out the pads,clean the crud off the exposed part of the brake piston and use the g clamp to push the piston back in,then grease up the brake pad sliding pin and put the pads back in

oil your chain aswell

satanicguardian · 16 Jan 2015 at 16:02

Ahh, now you say chain - I did recently replace my chain because my old one was stretched and floppy (giggity), I applied some WD-40 chain wax (spray can) about 2 weeks ago, do I need to be using it more often than that?

wazza300 · 16 Jan 2015 at 16:03

no it should be ok

tight spots like that are usually chain or pads rubbing,so best to check both while you have the back end up off the ground,or front end

satanicguardian · 16 Jan 2015 at 16:08

Ah ok, I've done about 8500km on my current discs/pads, should they be ok at this point?

wazza300 · 16 Jan 2015 at 16:14

idk but I would check them,see if theres any deep scoring on the discs and see if theres any meat left on the pads

that km works out to around 5400 miles so yeah I would certainly check them,they are probably very low or worn out by now

satanicguardian · 16 Jan 2015 at 16:25

Ahh ok, I need to work out how to get my back brakes off.. think it could be haynes manual time.. forgive my stupidity on this but is there anything I can take off that I won't be able to A) put back on again once removed, B) can leak and dribble etc?

wazza300 · 16 Jan 2015 at 16:27

nah its usually two bolts,allen key bolts that hold the back caliper on

undo those and wiggle the caliper off the disc,

you can look at the pad thickness without taking the caliper off though,if its worn down near to the metal on the pads then replace them

if its sticking then you need to take off the caliper/take the pads out usually held in with a r clip and a pin,and clean the piston and push it back into the caliper

theres plenty vids on youtube to give you the idea what to do

satanicguardian · 16 Jan 2015 at 16:38

Ah ok, it's a 14 plate sport style bike so I imagine they all use a similar system? Would I have to search anything specific on youtube do you think or are they all very much the same?

wazza300 · 16 Jan 2015 at 16:41

They are all pretty much the same,some of the nuts and bolts might be different

satanicguardian · 16 Jan 2015 at 17:01

Cool thanks mate!

I'll probably post again at some point tomorrow when I can't put it all back together again!

I can do PC's but bike mechanics is new to me..

wazza300 · 16 Jan 2015 at 17:06

you'll soon pick it up,if you lived closer to Dudley id do it for you,its pretty easy once you get to know how to do it

a very thin smear of grease on the back of the brake pads stops them squeaking aswell

satanicguardian · 16 Jan 2015 at 17:33

Ahh that's very kind, quite a way with dodgy brakes though but I'll keep it in mind for the future if the offer still stood?

and won't grease make them like..useless?

wazza300 · 16 Jan 2015 at 17:35

on the back of the pad,not the face that touches the disc

the part that the piston pushes against

satanicguardian · 16 Jan 2015 at 17:52

wazza300 said:
on the back of the pad,not the face that touches the disc

the part that the piston pushes against

Ohh.. I knew that.. I was just.. testing...

ShakenNstirred · 16 Jan 2015 at 18:19

satanicguardian said:
Ahh, now you say chain - I did recently replace my chain because my old one was stretched and floppy (giggity), I applied some WD-40 chain wax (spray can) about 2 weeks ago, do I need to be using it more often than that?

it depends on the weather and the mileage you do as to how often you need to do the chain

satanicguardian · 16 Jan 2015 at 19:01

ShakenNstirred said:
it depends on the weather and the mileage you do as to how often you need to do the chain

At this time of year probably only 500 miles a month, and well typical UK weather

satanicguardian · 19 Jan 2015 at 14:54

Update - Sooo I managed to successfully take apart, clean and rebuild my rear brakes, I used brake cleaner on all components and applied some light grease to the back of the pads/spring and pistons, reassembled and unbelievably it still worked!

It helped initially free up the back wheel, but this morning after a night in the cold garage it had seized again slightly.

I've been told I should make sure that the piston that pushes into the rear master cylinder is going in straight and true because this could make it seize, especially if the bike has been dropped.

My bike has only gone over once, and that was very gently being lowered onto gravel because I lost my footing and couldn't hold it up.

If it's not the above issue, can anyone else suggest why it could be binding when left standing for a while?

Cheers,

Jamie

wazza300 · 19 Jan 2015 at 15:00

probably the cold weather,once you've used it a few times it frees up

did you push the piston back inside the caliper? some red rubber grease might help

Fireskull · 19 Jan 2015 at 15:00

By take apart do you mean you took out the piston also? or just cleaned everything else?

If you have cleaned everything else then it will be a dirty piston and seals, new seals if they are in bad condition and clean up the piston, but this will require you to bleed the brakes once its all back together.
A lot of people just clean the outer seal without realising there is an inner seal and its this one that can cause big issues.