Avid Bleed Kit

[Rydogg]

Thanks to the guys at Action Cycling, I picked up my Avid Bleed Kit today for under R300.

 

I know, I know, a home made one would have cost way less, but it's not nearly as cool. Plus this kit makes it way easier.

 

http://farm4.static.flickr.com/3299/3225222613_ff408041a4.jpg

 

 

 

Anyway, just thought I would post this up here so that you guys know where to get one.

 

Also a bit of a rave for ACTION CYCLING in Cape Town.

021 425 6833

[AndreZA]

I don't know if you can have a full home made kit with those little screw in thingys.

[ichnusa]

sorry to burst your bubble, but check out this CWC deal

a pro avid bleed kit for R340

 

[Slowbee]

as a mini hijack ... if the brakes are a sealed unit, why would you need to bleed them ?

[Mecnic]

The oil degrades over time from the heat generated from braking, and DOT oil unfortunately also absorbs moisture.

 

So a bleed with fresh oil every now and then keeps them feeling crisp and great,

 

I overhauled a set of Juicy 7 Ultimates which weren't serviced or bled in 5 years the oil was black and watery and the piston seals were bone dry and sticky. After a complete strip down, clean, new seal here and there and a blled and they were good as new

[Slowbee]

Mecnic, I am not wanting to start a fight - but I still dont get it. If the system is sealed then moisture should not be getting in to the brake system.

 

Surely moisture is the only worry? The oil going black doesnt affect the way the brakes work or the quality of braking ?

[BikeMarketcoza]

yeah it also accumulates dirt and debris. another problem is sumtimes the brakes get air in then over time and feel spongy even though it is a sealed system air still gets in im not too sure how but the oil definately degrades

[Mecnic]

Mecnic, I am not wanting to start a fight - but I still dont get it. If the system is sealed then moisture should not be getting in to the brake system. Surely moisture is the only worry? The oil going black doesnt affect the way the brakes work or the quality of braking ?

 

No fight necessary, Hydraulic disc brakes sometimes have a mind of their own and I rate it's a bit of a dark art haha, but here an explanation.

 

The moisture thing is just a characteristic of the oil itself and is not a major problem on its own, however it is the moisture absorbed by the oil which boils when the brakes do overheat when being dragged on a long decent for example.

 

Heat is the major problem, as the pads heat up the pistons heats up and the heat is transferred to the oil and it in turn heats up that's why there is a built in reservoir with a diaphragm in the system to deal with any expansion caused by the heat.

 

The heat over time causes the oil to break down (Go Black and hinder performance, think suspension same effect, the oil doesn't work like it should)broken down brake fluid is a total different consistency to fresh brake fluid (More watery and thinner resulting in a spongy lever feel) also Dot4 and 5.1 isn't all that friendly to rubber seals and can eat rubber seals which then also contaminates the oil inside the sealed system which also causes a drop in performance (Don't worry the seal thing happens over a long time)

 

And as pointed out sometimes air somehow sneaks in or oil leaks out past a seal resulting in the little bit of air not properly removed from the in the reservoir to enter the system. Sometimes air is trapped in the deepest corners of the caliper where it stays for ages and eventually breaks loose and enters the system and then needs to be removed by bleeding it out.

 

It must be remembered very few brakes are bled by hand, most are done by machines which are set for x amount of oil etc etc so the chances that from the factory all the air is out of the system is slim, sometimes I have to even bleed my systems twice to get all the air out it happens.

 

So although the system is sealed, certain factors mean that a bleed or total replacement of the oil is necessary from time to time. The system in a car is also sealed however manufactures do recommend it to be bled (oil replaced) every so many years or km's

[The Drongo]

as a mini hijack ... if the brakes are a sealed unit, why would you need to bleed them ?

 

 

ONE WORD - DOT fluid!

[The Drongo]

See this fread:

 

https://community.bikehub.co.za/topic/102969-mineral-oil-vs-dot-5/

[Slowbee]

thanks guys.

 

I guess after 2.5 yrs its time to change the fluid on the brakes then, before something breaks.

[Thug]

There was a guy on The Hub, probably 18 - 24 months ago that made up these kits for R100 or so. I bought one at the time but nver got a chance to use it as I then bought a set of Hope brakes.

[Tumbleweed]

The moisture thing is just a characteristic of the oil itself and is not a major problem on its own, however it is the moisture absorbed by the oil which boils when the brakes do overheat when being dragged on a long decent for example.

 

Is the moisture actually absorbed by the oil, or just attracted to it. Would've thought they wouldn't mix.

[Tumbleweed]

sorry to burst your bubble, but check out this CWC deal

a pro avid bleed kit for R340

 

 

Crikey, that's not bad. MBUK had a small insert on it in the April issue, and had it retailing for also 60 pounds.

[29thumbs]

A word on avid.

even when new, outa the box, reblead them.

i promise, there is a uge diff to be felt, and we proved it.

reblead your new elixer 5's with a decent grade Dot 5 and you will experience a very diff brake.

 

Just do it.

[Mecnic]

Is the moisture actually absorbed by the oil, or just attracted to it. Would've thought they wouldn't mix.

 

The Dot and moisture (Water) actually do mix and stay mixed it doesn't separate out at all over time. It's a very strange characteristic