Binding front brakes

[gt185]

Just fitted new brake pads all round, and while the back brake is fine, the front ones
seem to be binding a bit. They stop the bike fine, and seem to release, just not
enough, which makes manouvering the bike a real struggle. There was so much
crap all over the brakes from riding through part of the winter, I don't know if the
pistons aren't moving a freely as they should.

cheers

[masterofinsanity]

whip em out and clean em up.

[RedexRobB]

Best thing to do is get the calipers off and give them a thorough clean with a toothbrush and some brake cleaner. Squeze the lever to bring the pistons out a bit, clean them, then cover the piston surfaces with rubber grease and push them back in. The rubber grease will protect the pistons from corroding again and i think it it acts as a lubricant too.

Just be careful not to push the pistons out too far, you should only need to see about 5mm of the piston to clean it.

[gt185]

Just had a look at the manual on this site. Says use a wooden block/rubber
seal and compressed air. Is there an alternative to compressed air? Or a way
round it?

[masterofinsanity]

duplo blocks work great for cleaning calipers mate

[gt185]

Rob, I think I prefer the option of not taking the pistons all the way out as you've suggested.
Should make it a bit easier.

Duplo blocks?

[masterofinsanity]

see pic

[RedexRobB]

you only need to do that if your taking the pistons out, you only need to see the first 5mm or so. If some are stuck then yeah use a wooden block and or a clamp to hold them, the lever pressure alone will be enough to push any stuck pisons out, keep pushing it in and out with rubber grease on and that should free it up.

[gt185]

Rather than look daft and say Duplo blocks? Like big lego? I left the lego
comment out, in case duplo is a brand name for something bike related......

[RedexRobB]

Rob, I think I prefer the option of not taking the pistons all the way out as you've suggested.
Should make it a bit easier.

Duplo blocks?

If they are still like it after youve cleaned them up then you may need to put new seals in, but theres no point going to all that expense while you can try the simple stuff which might do the trick.

Duplo blocks are big lego for kids

[RedexRobB]

too late ive got quoted

[masterofinsanity]

yeah you use compressed air if you're taking them out, to clean them just pump the lever a bit.

[gt185]

I'm just thinking, the trick must me to get all 4 pistons out at the same time/level.
Some are bound to be freer than others. The duplo block will stop them coming out
too far right?

[gt185]

I'm not so sure (hoping) that the seals are gone, as the brakes were fine before
I put the new pads in. Obviously the pistons had to be pushed further back
to accommodate the new pads, so I'm thinking that any crap that was on there,
has been pushed further in (to the seals?).

Brake cleaner, tooth brush and rubber grease. Need to go shopping again.

[masterofinsanity]

stick a duplo block in 1 caliper after you have cleaned the pistons cos if you push the pistons back in that may be corroded they will rip the piston seals, this will then give you more leverage to push the pistons out on the other caliper for cleaning.