Hi all

Last night I had a near miss at a very busy junction thats at the bottom of a very steep hill on my Scandal using Formula K24s (bought 2nd hand from this very forum).

The front brake, over the space of about 20m, locked up completely. Right in the middle of said busy junction, luckily avoiding getting mown down by crazy london agro drivers.

They locked up completely with the pads actually locked onto the rotor (without me pulling on the lever at all) – So much so that when I managed to drag my bike onto the pavement, it took me a lot of effort to get the pads out to actually enable me to get home ok (albeit without front brake).

With wheel out & pads removed, both pots have now moved so far out that they themselves touch the rotor (when wheel is put back in place). I cant get the pots to sit back in their usual position so cant get the pads back in so cant run a front brake.

I'm also very wary of what happened & it happening again as it scared me sh@tless & very nearly caused an accident.

Any ideas? Never experienced anything like it on any of my previous set ups – Juicy 3s & XT, and I'm at a loss as to what to do next. I dont want to force the pads in any more than I already have (tho the manual does suggest using a screwdriver to push them back in which i've already tried but it feels like theres too much resistance).

I dont have a bleed kit (yet) but I reckon I need to relieve some pressure, get the pots back in place & then bleed.

Does that sound about right?

Any help/advice very greatfully recieved

Cheers

There was a problem with early ORO's. The master cylinder piston in the lever sometimes swelled because of the DOT fluid. Might be the cause of your problem?
The original piston was a grey plastic, new ones are metal. Having said that, my grey plastic ones have been fine so not all brakes are affected. If this is your problem you'll need http://www.chainreactioncycles.com/Models.aspx?ModelID=22475

Simple to fix.

thanks for` that – I'll look into it.

On another forum someone mentioned that there might have been too much dot4 in there & under heat its expanded & pushed the pots out.

This kinda makes sense as the front brake exerted a lot of stopping power with not much lever action (didnt think anything of it at the time & thought it was just the way previous owner had them setup).

I run K24's & apart from the problem mentioned above about the master cyclinder piston they have been great.

Given your near escape I would be tempted to speak to Propel & ask them about it, they are the distributors for Formula so they should know what the problem is & more importantly how to fix it.

Yup – spoke to Propel & they suggested the too much Dot4 as a possible reason.

They also suggested a quick way to expel any excess Dot4 without the bleed kit so I'll give that a go & let you know what happens

Cheers

Hmmm

The trick to remove excess oil resulted in me removing too much Dot4 so I had to go & get a Formula bleed kit.

Now got that I've got a Formula bleed kit I'm having trouble bleeding my K24s.

After connecting both syringes with the correct amounts of oil I'm not able to push oil from the calipers upto the lever – theres no movement whatsoever.

Likewise from lever to caliper BUT when i pump the lever I can feel & see the oil rise/fall in the caliper syringe.

According to the destructions I should be able to pass oil from one syringe t'other

Any ideas?

Cheers

sounds to me like a problem with the seals in the master cylinder – or something blocking the passageway from the reservoir to the master cylinder.