Mountain bike hydraulic brake sticking on

alun4

I am on holiday in France and have an Orange Patriot Downhill Mountain Bike. The front brake is an Avid Code 2 and the brake is sticking on today. I don't speak French so would welcome any thoughts as to the cause before going to a shop to get the problem sorted. If I release the front wheel and spin it the brake pads seem to unlock but as soon as I apply the brakes again the pads stay out against the disk.
If I was at home I would go to a local I could really trust but as I have only got 2 more days holiday this is really urgent and any cycle repairer is a long way down the mountain!

Weird_Nev

"Escuser moi monsieur. Mon frein A l'avant ne functionement pas!"*

Pull the pads out of the caliper and clean around the piston face? If it's old and gunked up it may need the piston pulling out of the caliper and cleaning and putting a new seal kit on there.

*may illicit varying amounts of confusion and or laughter.

The_ICT_Engineer

Take the pads out and inspect the braking surface. If a ridge has worn in the surface of the pad where it meets the edge of the disk This can cause binding of the type you have. A quick repair is to file down the ridge, but the pads should be replaced as soon as possible.

Richard53

"Mon frein avant est colle" - my front brake is sticking. (That last 'e' has an acute accent, 'collay', but for some reason it won't work here.)

I have never dismantled a bicycle hydraulic brake, but if the mechanism is anything like a motorcycle brake, it's highly likely the piston is sticking. Take the pads out, press the lever so the pistons come out 1-2 mm (no more than that or they will pop out altogether), clean round the piston with a cloth/toothbrush and whatever solvent you have to hand, push the pistons back in with a finger, replace the pads, squeeze the lever a few times to seat the pads, and you should be good to go.

(That's bush mechanics, side of the road stuff. Obviously there is a better procedure when you are at home with all the kit and a cup of tea nearby.)

alun4

Weird_Nev wrote: »

"Escuser moi monsieur. Mon frein A l'avant ne functionement pas!"*

Pull the pads out of the caliper and clean around the piston face? If it's old and gunked up it may need the piston pulling out of the caliper and cleaning and putting a new seal kit on there.

*may illicit varying amounts of confusion and or laughter.

Thanks for the advice, when I removed the pads I found they were very worn and the spring was part broken.

alun4

The_ICT_Engineer wrote: »

Take the pads out and inspect the braking surface. If a ridge has worn in the surface of the pad where it meets the edge of the disk This can cause binding of the type you have. A quick repair is to file down the ridge, but the pads should be replaced as soon as possible.

The pads were worn but it was a problem getting replacements for per 2011 Avid Code2 in Bourg saint Maurice ..... I did find the last pair. Thanks again.

alun4

[QUOTE=Richard53;62929832"
I have never dismantled a bicycle hydraulic brake, but if the mechanism is anything like a motorcycle brake, it's highly likely the piston is sticking. Take the pads out, press the lever so the pistons come out 1-2 mm (no more than that or they will pop out altogether), clean round the piston with a cloth/toothbrush and whatever solvent you have to hand, push the pistons back in with a finger, replace the pads, squeeze the lever a few times to seat the pads, and you should be good to go.

[/QUOTE]

Thank you also, very hard to get the info in such quick time when on holiday in a foreign country. Without all the help it would have taken away from my holiday.
It says so much about the MSE community.

I damaged one of the piston heads getting the pistons to slide back in. The Avid piston heads are like a cylinder (rim of a can) with a domed rebated centre which locates into the rear of the pad. Luckily they are quad piston heads in the calliper.

I have got a bit of a rub and it was very difficult to get the new discs into the calliper but it saw me through the weekend and I will be in a better position to send photos of the damage when I return to Wales.

Many thanks for these informed replies .... You saved a holiday!

Alun