sticky dual pivot brakes

craker

from my 2005 Tiagra groupset. I've been commuting on the bike over winter...

Without a cable the brake (it's just the back one) doesn't spring out very far.

Now I had a quick look at the park tools website and I got to the bit where I'm taking springs off and - for whats surely just a grimed up component - that's too much disassembly.

Any tips for cleaning a lubing without a stripdown? Hot oil bath? Have I missed a screw that makes the spring force(s) higher?

redvee

IIRC cheaper Shimano callipers were quite easy to strip for a relube, done it a few times with Shimano and Tektro DP callipers.

http://techdocs.shimano.com/media/techd ... 609046.pdf

Undo bolt 1 and remove the arm, that now gives you access to the main pivot bolt. Grab the nut on the back of the calliper with some pliers and undo this, making sure you keep the washers as they fall off. Clean the bolt up and grease and re-assemble, might take a bit of time first time but should be 10-15 min job after a few attempts.

Nigel Bennett

My elderly 105 levers suffer from weather after a while - as redvee says, it's not difficult to take them to pieces, clean and lubricate and re-assemble. A digital camera helps when dismantling so you get it all back correctly!

I would take issue with his rather brutal "Grab the nut with pliers" bit - NO! USE A CORRECTLY SIZED SPANNER!

Also on 105 and Ultegra, there's a small grub screw (Item 2 on the picture redvee shows) which can be a sod to undo - I've drilled one or two out as they've corroded in place. Once you do get it out, use anti-seize on it when refitting it.

On the 105 & Ultegra brakes, the thrust washer (the one just above the grubscrew in the picture) has tiny ball bearings in it. No idea if the Tiagra one does, but take care not to lose them, as they can easily ping out and away into the darkest recesses of the shed...

Make sure you take all the play out of the pivots by adjusting the end-float; the nut, washer and bolt (marked 1) is simple; tighten up the screw until it's a bit stiff, then back it off a bit so it frees up. Nip up the nut with the spanner (10mm A/F) whilst keeping the screw from turning with an Allen key.

Same method applies to the other pivot fasteners - marked 3 - and lightly nip up the grub-screw 2.

Very satisfying to get them all working smoothly again afterwards.

rake

one of mine did this. i just loosened the pivot bolt a small fraction of a turn and its fine now. i dont know if 105 you can do this.

redvee

Nigel Bennett wrote:

I would take issue with his rather brutal "Grab the nut with pliers" bit - NO! USE A CORRECTLY SIZED SPANNER!

There isn't a nut with flats for a spanner in the commnet I made, it is the nut that goes against the fork crown.

Nigel Bennett

Ah yes - the oddly-shaped one. It does fit a ring spanner with double-hexagon drive; IIRC it's 13mm AF.

antfly

Clean it and spray it with GT85, forget all the disassembly crap.Works like a charm.