bled brakes not working right

lee1972

I have brought shimano kit and bled the brakes
still not much preasure in the lever
and back pads going on and of but not enough and squeaking a lot

any ideas
thanks lee

nicklouse

The brakes are?

How can there be no pressure in the lever but he brakes lock on?

Needs looking at by someone who knows what they are doing.

BG2000

When you pull the lever, do the pads go tight up against the rotor, and is there at least some pressure in the system, or does the lever just go right up against the grip ?

It sounds quite clearly like a major lack of brake fluid. If in doubt, you really need to flush out all the old fluid and make sure you fill it right up with the correct stuff, i.e. mineral oil for Shimano, Dot 4 or 5 for others etc..

Go easy on the pistons when you push them back in place, as maybe they've seized a bit and need lubing.

If you're really worried and don't have spare fluid, tools, experience, and don't care about matching brakes, look on eBay, you'll pick up a cheap working rear brake for peanuts....

lee1972

yes pads go right up to the disc
lever goes right up to the handle bars

mate has put some brake fluid in tonight but just pushed it through with a syringe type thing
till it came out the other end

is it worth me taking the pads out and getting wd40 on the pistons and trying it

lee1972

just a thought the pads he took out was realy low and sticking on
that's why he said needs new pads

could the pistons need resetting ( if so how do I do this )
im all new to this and haven't had a bike since I was 16 lol
so they have all changed since then

BG2000

not sure what you mean by 'sticking'.

if you're saying the pads stay tight up against the rotor (disc) then the pistons might be sticking, but a severe lack of fluid could also have this affect.

don't put WD40 anywhere near your brakes (or anywhere near a bike for that matter).

if you say what brakes they are, someone here might be able to recommend a piston lube...sometimes you can use brake fluid if that's what your brakes use inside...otherwise some kind of telfon grease perhaps ? it depends what your piston seals are happy with.

cooldad

What sort of brakes are they? See Nick's post and BG2000's. Depending on the brakes, brake fluid might be the wrong stuff to put in.
If the seals need a lube, use whatever is in the brakes, either fluid or mineral oil.

WD40 has no place anywhere near your brakes or anywhere else - great way to trash the seals, amongst other things.

lee1972

shimano and caliper br-m445

BG2000

Decent brakes those, if in working order

They take mineral oil - nothing else !

http://www.chainreactioncycles.com/Mode ... delID=5620

I hope your mate put this stuff in. It's not as commonly available as Dot brake fluid, i.e. you don't buy it from Halfords, only a decent bike shop.

lee1972

oops no he didn't
what size would I need to do the back brake
as seen them on ebay with the bleeding kits

cooldad

You need to get the brake fluid out quickly, or it will destroy the seals. Then flush them out with mineral oil. And maybe flush them again.
And if you're lucky they'll still work.

cooldad

As for bleed kits - google Epic bleed kits. Come with oil and you don't need very much.

lee1972

cooldad wrote:

You need to get the brake fluid out quickly, or it will destroy the seals. Then flush them out with mineral oil. And maybe flush them again.
And if you're lucky they'll still work.

when you say quickly
its that as in I should have already done it ??

as got to order a bleeding kit first as got nothing to get it out with
would it be ok till Saturday?

or is the damage done?

The Rookie

BG2000 wrote:

you don't buy it from Halfords, only a decent bike shop.

Oh please....Halfords stock perfectly good Mineral oil.

Quickly = NOW, may already be too late, DOT will 'rot' the seals

lee1972

to late then as the earliest I will get it out is tomorrow
as got nothing to get it out with
had to order a kit of ebay

lee1972

I have brought shimano kit and bled the brakes
still not much preasure in the lever
and back pads going on and of but not enough and squeaking a lot

The Rookie

Have you bled them properly?

Without being rude, but the tale of disaster above suggests a lack of confidence on our part wouldn't be unfounded! In the first post you'd bled them (which if done properly means they would be full), then filled them with completely the wrong stuff (what happened to the stuff you bled them with in the first place - you know to bleed them you have extra fluid right?)

Describe how you bled them please.....

cooldad

And how you flushed them out first.

lee1972

yes flushed the old stuff out
used 200ml of shimano mineral oil so presume it was enough

had to work from caliper with the syringe and pipe
as couldn't get the bit of the brake lever as the allen key has rounded off

there seems pressure in the lever now
and they do work if you pull the lever

but if I ride it and brake keeps making a squeaky noise and bakes don't work very good
never took the pads out as I now know I should have
but have taken them out and heated up on the hob to help dry them out

could they need bleeding again at a shop as it was my first time and didn't realy know what I was doing

front brake was fine I never touched it but that's squeaking now
so wondering if some oil ran down into that to

lee1972

have been told to take a ride down a long hill with the brakes on
should that make any difference

ricardo_smooth

sounds like the pads are contaminated at best......new pads and degrease the rotors. If you can't get the allen key fitting out of the lever end. You won't ever get all the air out of the system. Out of interest, how did you get the old stuff out if you can only get one fitting open?

lee1972

managed to get the main one on the lever off
but when I looked at some guides it shows you taking the other 2 out and putting the oil in lever end
I couldn't get the 2 out to show the fluid in the lever
just the main one

so had to use the syringe on the caliper end and push the mineral oil through
and catch the other stuff coming out of the lever

probably haven't done it right lol as 1st time
but back brake wasn't working at all before

The Rookie

So do you have the fill/bleed funnel? (item6 http://techdocs.shimano.com/media/techd ... 702224.pdf)

Have you read how to bleed them? http://techdocs.shimano.com/media/techd ... 689046.pdf

As you can't remove the cap (Find a way to!) then you need to make sure the point where the funnel attaches is the highest point of the reservoir so it bleeds air out.