Seized 4-pot calipers?
Discussion
Im getting alot of vibration related noise from the 4-pot front brakes on my Classic. Im suspecting sticky pistons are to blame; the rubber piston seals weren't too healthy last time I checked. So to remedy the situation, Ive a full set of disks/pads, and a seal kit to fit.
Does anyone here have experience with freeing out & cleaning up these 4-pot calipers? Im hoping its not an awkward job!
Does anyone here have experience with freeing out & cleaning up these 4-pot calipers? Im hoping its not an awkward job!
A bit of feedback!
I changed the discs and pads before the Christmas break. On closer inspection, I found three of the eight rubber dustboots were split on the front calipers. There was evidence of rust on those pistons and they were tighter to actuate than those with intact boots; almost seized in fact.
I advanced them out, one at a time and cleaned the chrome surfaces with 2000 grit paper, then lubed the piston with clean brake fluid. The old dustboots were then replaced with new. All sliding surfaces were copper greased. I also bled the system and flushed out the old brake fluid with new.
Inspection of the discs showed extensive radial cracking, but very little actual disc wear. Its likely this was due (in-part) to glazed rear pads and old discs. It would seem the fronts were doing all the hard work and getting very hot as a result.
Anyway, the pedal feel is now very well weighted and not as 'wooden' as it felt before. The vibration is also gone.
An easy job all round
I changed the discs and pads before the Christmas break. On closer inspection, I found three of the eight rubber dustboots were split on the front calipers. There was evidence of rust on those pistons and they were tighter to actuate than those with intact boots; almost seized in fact.
I advanced them out, one at a time and cleaned the chrome surfaces with 2000 grit paper, then lubed the piston with clean brake fluid. The old dustboots were then replaced with new. All sliding surfaces were copper greased. I also bled the system and flushed out the old brake fluid with new.
Inspection of the discs showed extensive radial cracking, but very little actual disc wear. Its likely this was due (in-part) to glazed rear pads and old discs. It would seem the fronts were doing all the hard work and getting very hot as a result.
Anyway, the pedal feel is now very well weighted and not as 'wooden' as it felt before. The vibration is also gone.
An easy job all round
Edited by MLoc on Friday 27th December 09:12
Edited by MLoc on Friday 27th December 09:13
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