In need of help with brakes

[munkeyboi]

Hiya all,


Me again throwing myself on the mercy of the court for assistance. :grin2

So here's wassup:

Bought some new brake pads, front and back for my TZR 125 1990 (I think), I think they are the right ones.
I took the old ones off (one side was more worn than the other) but they still looked ok.

Tried to fit the new ones, they wouldn't fit, the space between the pistons was too small. I tried to prise them apart by hand and then with pliers, but it still wasn't enough. I noticed that one piston was still out more than the other.
So I tried to put the old ones back.
OMG, They fitted in but i couldn't get it on the disc.
So i tried to take the whole thing apart, but i only managed to get it in two pieces (I couldn't dismantle it in to it's components as the haynes manual shows)
Got brake fluid all over my trainers too :(

Finally i managed to get it all back together and bled it.
The brakes aren't as sharp as before, but fairly close.

Suffice to say I left the back brake well alone!!!!!

So what's going on with my brake callipers?
Is one piston meant to come more than the other?
How the fu*k can I fit the new pads and have the pistons even (If they are meant to be)
How far in the calliper are the pistons meant to go?
Will i need to replace the calliper

Basically HELP lol ;)

Cheers

David

[gixer400]

i have so much trouble with brakes, they either dont wrk or they lock up.

to fit new pads without dismatling, keep your old pads(they will help later).
righty, what to do is take your old pads out, and clean your caliper and pistons with brake cleaner and wire wool or a cloth. (to make this more effective pull the brake slightly when it is off the disc to move the pistons out a bit, but not too much)
when your pistons and caliper are clean put your old pads back in, and use a large flat head screwdriver of something of the sort to lever them in. if there is a bit of a gap between the pads (there will be afer a bit of levering) put another old pad in and begin levering again. do this until your pistons are fully in, remove the old pads and put sparkly new ones in. remember to keep the old pads though, they are very handy. you can use a bit of wood or something, put i prefer old pads.

and to make your brakes a bit sharper i will pass on some knowledge given to me by falloff.
what to do is, pull your brake lever in as far as it ill go, and put a cable tie on. keep it on for a few days, and before you take it off knock your caliper a bit and the lines to release any bubbles. when you take the cable tie off release the lever slowly then pump it, you should feel a difference straight away. i do.

it could also be that new pads take time t bed in. after a bit the will get better.


i hope i was of help on these things, sorry i cant help with the rest. :)

[Lateshift]

This may be a bone question, but i am assuming you did take the fluid reservoir cap off to release the back pressure when you are trying to move the pistons back in here? ;)


Firstly its quite common for some bikes to have slightly uneven pad wear, pressure in the hydraulics isnt always distributed evenly due to the distances between the brake line and actual pistons, meaning that if one pad is slightly further away from the brake line there is slighly more fluid to compress first, this becomes more noticeable if the fluid is old as it compresses easier.

Gixer400 is bang on the money as far as changing them and cleaning them goes, however before you put the pads in get a small pievce of emery cloth or a file and gently smooth a 45 degree angle on to the edges of the pads to stop the rough edge biting the disc, it will help them bed in more smoothly and also eliminate the squeaking you tend to get initially with new pads.

Also remember to use copper grease or other similar anti-sieze compound on the "back" of the pads before you put them into the caliper ;)

[munkeyboi]

Cheers Guys


Yeah Lateshift, I removed the brake fluid lid when i tried to split them apart, still didn't shift em tho.

I'll try your handy tips later guys

Cheers

David

[gixer400]

Gixer400 is bang on the money as far as changing them and cleaning them goes,
yay, ive been recognised by the pres,:jumping2
i am honoured

[munkeyboi]

Thanks again guys,

Went to the motor shop and got everything (except the tube for bleeding the brakes)

Gonna have a go in a minute, I'll let ya know how it goes.

Cheers

David :)

[gixer400]

have fun. the brakes are one job i hate with a passion.

ive rebuilt a tzr engine, hat was a walk in the park, ive just akmost finished rebuilding my zxr engine, and im enjoying that. but i screamed and cryed when fitting my braided lines.

[munkeyboi]

lol,

Well mate, when I say my knowledge of bikes can fit on the back of a postage stamp, I'm not lying.

I honestly know nothing, but I'm on a steep learning curve. I've just bought the haynes manual and I'm trying to work my way through the servicing part.

I'm fairly skint and need to get my bike road-worthy. Also I do wana learn how to do bits and pieces to my bike, it can't be that hard (or so i thought)

Unfortunatley my mate, who was my bike guru and ex-instructor, has gone to that big race track in the sky a few weeks ago. So I'm on me own, well except this fantastic forum.

So ya never know mate, once I'm up to speed on all things two wheels, I could become a bit of a brake expert and I'll come do yours (in a century or two)

lol

[gixer400]

if your interseted in learning how they work (helps with fixing) and also how to use tools, which tools are best for different jobs etc, then i cant rate the haynes motorcycles basics techbook and motorcycles maintenance techbook highly enough. i have these and have helped a lot. i started not even konwing what the carbs were. now i can do most things.

link: http://www.haynes.co.uk/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=10001&storeId=10001&categoryId=21001&langId=-1&parent_category_rn=10004&top_category=10004

[munkeyboi]

Cheers Mate,

Thanks for the link
Changing the pads part 2 was a resounding failure.
I got all the bits, cleaner, wool, grease etc
Tried and failed, couldn't get the pistons to close properly.
One of them is definatley screwed. On comes out a fair bit on pressing the brake, the other doesnt even move.

Dunno what to do, replace it i guess.

PS Why does it say 50cc Moped Massive below my name, c'mon, i know it's not much of a difference but I'm a 125 dude

[EverSoSlightlyFasterThanU]

i havent read this thred yet but if you have a hammer make sure you dont know where it is

[munkeyboi]

lol

It took a few taps of the rubber mallet to get the bloody callipers off.


I'm glad i dunno where a chainsaw is, otherwise i'd go nutz with that!!

hee hee

[flatty01]

wen ya break calipers are off releas the blead nipl and push the pistons back with a G clamp . But if one cums out further than other then try and get the pistons to cum right out they could be full off muck and stuff give it a go ya got nout to luse bt be carefull wen puting the pistons back in incase you bread the seals :reading