Garbage brakes!

[Wabby]

Hi Guys,

Well, for the bikes MOT I had to clean the brakes up etc in order for them to not stick, and brake at the same time.

Since then, they have got gradually worse, until the point where you can hold them right in and still accelerate (slightly).

I cleaned them again (pistons still in brakes, and still attached to bike) and red rubber greased them again, and they were 'ok' for a few hours, and are now back to the previous point.

Stages to sort?

Would bleeding be the first option? (If so, how?)
Rebuild master cylinder?

The pistons themselves move quiet freeley, just not at the same pace (when looking and pulling the lever).

The fluid in their is at least 3 years old I think, and has never been changed since I had it or the previous owner had it stood up.

Cheers

[extonyg]

ye if the pistons seem free and clean then yes i would be doing a brake fluid change as its advised every 2 years atleast i think, might be worth rebuilding the master cylinder if it hasnt been done in a while as well as this gave a great improvement to the 'feel' through the lever on my bike

[cargo]

3 year old brake fluid is certain to be fecked............................................

I change brake fluid every other race....................it's cheap and easy to do and it might just save your life

[Wabby]

3 year old brake fluid is certain to be fecked............................................

I change brake fluid every other race....................it's cheap and easy to do and it might just save your life

How do I do it?

Do I need one of those dual bleeding kits, to do both calipers at once?

Not done it before, so tips/guidance will be appreciated!

Cheers

[RedexRobB]

Theres various ways of doing it. I use a vaccum pump gun and a small sealed pot to suck the fluid into while topping up the fluid reservoir. So long as you keep the reservoir full up top you wont suck any air in. Oh, and you do one caliper at a time.

[extonyg]

i just do it by pumping the lever so the fluid comes out, i have a piece of pipe and a bottle collecting the used brake fluid, keeping the level topped up so no air gets in and then once i have pumped enough out hold the lever at the bar and tighten the bleed nipple up then the same for the other caliper.pretty easy no special tools req.

[Wabby]

Fitted braided lines.
Bled system (no air bubbles in fluid)

Brakes still shite!

Whats next?

Any ideas?

Really pissing me off.

[RedexRobB]

rebuild the master cylinder id say.

[Wabby]

Can I replace it with an 'upgraded' one from another bike?

Which would fit if I can.

Really pissed now - Spent £70 so far (2 x calipers, braided hoses, dot4) and still toad brakes!

I just want to be able to stop on a dime.... lol

[Wabby]

To make matters worse, I just cleaned up my old calipers, and theres f*** all wrong with them!

:smt013

eBay I think. Might aswell sell the rest of my toad while I am at it!

[extonyg]

ye sell off your calipers to ragain some money, i would be rebuilding the standard master cylinder i did it on mine and the brakes were so much better afterwards i brought a kit of ebay only £20 or so worth doing.as its the m/c that actually makes the pressure in the lines so you can have amazing calipers and a shite m/c and the brakes will still be rubbish.
hopefully once you have done that they will be all sweet.

[Wabby]

OK.

Quick run down:

1) I have fitted braided lines. They are fitted correctly, and are torqued correctly
2) I have re-built the master cylinder
3) I have replaced the calipers with a 'known' working set

I still cannot get 'good' pressure.

I can pull the lever to the bar if I try, and it doesn't 'bite' until about 1 inch from the bar.

Any ideas to get the pressure up?

REALLY pissed off with this now, wish I never started!

[Mad Phil]

i just do it by pumping the lever so the fluid comes out, i have a piece of pipe and a bottle collecting the used brake fluid, keeping the level topped up so no air gets in and then once i have pumped enough out hold the lever at the bar and tighten the bleed nipple up then the same for the other caliper.pretty easy no special tools req.

You need to pump through & lock the nipple on each pump B4 releasing the lever..

ie release nipple, slowly pull in lever to bar, lock nipple, release lever then back to release nipple again.

Another thing that some times works is to on a cycle where the lever is at the bar & nipple just locked, tape the lever to the bar overnight with the MC top loose & any aiy may rise up & out. Obviously needs doing for both sides.

[Wabby]

I have done whats been said there, thats how I have the 'little' bit of pressure.

No air coming out with the fluid.

Think I might drop it into the local garage and ask them to hook up pnuematic pump to solve all this messing around.

[hciR]

I use a large syringe with a hose attached to it and just suck the fluid through. Can get em pretty good like that, then squeeze the leaver in and tie it to the bar, and leave it over night to help free any more air.