Mini ally pot reservoirs

[cabbie]

Had the front brakes lock solid today, got radial gsxr K9 front calipers with new pads new discs, radial master in off Triumph 600, had to loosen the master cylinder bleed nipple to get the brakes off, I have the mini alloy pots, I read about a few guys having their brakes lock up due to the mini pots, anyone else having issues? I bought mini Brembo plastic reservoirs ages ago so might just swap over, don't want to have the brakes lock up miles from home!

[RevHead]

i bought a brand new 2012 radial brake master cylinder for my busa ,ive been having problems with ,the front brakes slowly coming on ,not locking ,but coming on by themselves,i just crack the banjo bolt to release them,i bought braided lines from and english company,im going to replace them ,as im sure there the cause of my problem,bc everytime this happens i do afull re-bleed ,and the lines are full of air? got me!
oh im running 1999 tls front calipers.

[Chase]

Did you get a diaphragm with them? Without one they will lock because it creates a vacuum in the reservoir.

[TonyOW31]

Check your lever, I've seen a lot of this with radial master cylinders and incorrrectly fitted levers, some of the cheap chinese ones need modifiying to stop it happening.

[cabbie]

Check your lever, I've seen a lot of this with radial master cylinders and incorrrectly fitted levers, some of the cheap chinese ones need modifiying to stop it happening.

Modding where Tony? I'm going to remove the mini alloy pots anyway.

[ALBI]

get new ones from exben and problem solved

[cabbie]

get new ones from exben and problem solved

Who is exben?

[TonyOW31]

Modding where Tony? I'm going to remove the mini alloy pots anyway.

usually around the area of the pin that pushes on the piston, or the pin itself. If you feel the lever there should be a bit of play before the piston is actuated, if that isn't there, as the fluid heats up and expands there is no where for the lever to go, so the brakes start applying, the fluid then gets hotter, and the brakes go on even harder, then they lock on.
Can't really see the mechanics behind the reservoir causing it though, not unless it is way over filled?

[wackyrider]

Who is exben?
Exben is a long time member and owner of Extreme Creations (http://www.extremecreations.com.au/). He makes some wicked billet reservoirs. I have a set on my bike too. Professional bit of kit and worth the money.

[cabbie]

usually around the area of the pin that pushes on the piston, or the pin itself. If you feel the lever there should be a bit of play before the piston is actuated, if that isn't there, as the fluid heats up and expands there is no where for the lever to go, so the brakes start applying, the fluid then gets hotter, and the brakes go on even harder, then they lock on.
Can't really see the mechanics behind the reservoir causing it though, not unless it is way over filled?

Nope there is zero play in the lever, will trim the pin a bit, some say the alloy pots cause a vacuum as there is no diaphragm to move down with the fluid, going to replace them anyways.

[wackyrider]

You need to have a diaphragm in the reservoirs to compensate for the movement in the fluid level as you are actuating the brakes as the last thing you want is for air to go through.

As for the lever, the pin doesn't need to be trimmed, it's the section of the lever that prsses on the piston (to actuate the brakes). File a bit off so that when the lever is in place there is a bit of freeplay as Tony said.

[cabbie]

Yep will do, machine lever and replace reservoirs, check.

[wackyrider]

2835

Lower picture is the modified lever

[Gix11]

Who is exben?

Ben Shaw. Here's his billet resevoirs: http://www.extremecreations.com.au/Store.aspx

[ALBI]

yep dat him^^^^^^^^

[Deano]

It's the res causing the problem. Change to one with a diaphragm and you will be right

[TonyOW31]

It's the res causing the problem. Change to one with a diaphragm and you will be right

I really can't see that, if it's causing a vacuum, then it should have the opposite effect, I could understand if it was pressurising, but I just can't see the mechanics behind the fluid reservoir causing the problem.
I've seen/fixed this problem seven times on various different bikes, and in every case it's been the lever.

[Redmohawk]

What happens is the fluid drops on application of brakes causing a vacuum above fluid in res , this draws air into the res. As brake fluid heats up it expands taking up more volume in the brake system fluid trys to return into res at a lower pressure than the initial vacuum the resistance caused by the lid is enough to stop some of the fluid getting back into the res. This results in a slight pressure build up in the system.

As the system is set up to multiply force to the brake pistons the slight pressure acts on the brake pads and slowly your brakes become stuck on. The easy fix for the mini units you have is to get some brake "Res diaphrams" and drill a small hole in the lid. Or just bite the bullet and get some of bens very nice units.

If your a dodgie fucker just drill a 0.6 mm hole in the lid and change your fluid often.

[yuma bizl]

hey red. u know so much random stuff. good work

[Redmohawk]

Deano and a few others all knew it , I just gave the long winded explanation.

[Deano]

red is 100% correct. no area for the fluid to expand into therefore brakes slighty start to drag causing more heat causing more expansion causing more pressue on the pads and on the cycle goes. well until the front brakes stop you that is. wait for everything to cool down again and off you go till you need the brakes again and you start the chain reaction once again

[cabbie]

Off to garage to fit the mini Brembo plastic rezzies, don't want that again.