Brakes dragging/sticking

**motorbyclist** · 2nd July 2008, 15:47

Originally Posted by Chrislost

undo the pins that the pads slide on

take your calipers off

clean the pistons, sand the pins lightly(to clean them not more!)
put everythign back in the same places, making sure that the pads contact the same part of the disk that they were beforehand.

with soapy toothbrush i shall do this later tonight, along with checking alignment

**Chrislost** · 2nd July 2008, 16:09

Originally Posted by motorbyclist

with soapy toothbrush i shall do this later tonight, along with checking alignment

dont drop that soap aye!

*muttering* dam honder riders

**kiwi cowboy** · 2nd July 2008, 18:00

Originally Posted by Chrislost

dont drop that soap aye!

*muttering* dam honder riders

:angry2 NUFF BOUT ONDA RIDERS OR YOU GET DA

**FROSTY:Me** · 2nd July 2008, 18:57

Dude think this through.
Brakes were all good-no issues
Wheel taken out -nothin else disturbed
Wheel put back in -brakes suddenly shite

Conclusions I'd draw are A assembily process you used was wrong
Mouldy suggested one possibility -leg over too far -and also pspacers wrong
If not
Try removin one caliper and see how the wheel spins--then refit it and remove the other caliper--at least then the issue is isolated to one side

B replacing the bearings might mean that the disk no longer "slaps" the pads back -I doubt it but if thats the case then piston clean up / fresh fluid time and all will be back to spongyness

**motorbyclist** · 2nd July 2008, 20:29

Originally Posted by FROSTY

Dude think this through.
Brakes were all good-no issues
Wheel taken out -nothin else disturbed
Wheel put back in -brakes suddenly shite

Conclusions I'd draw are A assembily process you used was wrong
Mouldy suggested one possibility -leg over too far -and also pspacers wrong
If not
Try removin one caliper and see how the wheel spins--then refit it and remove the other caliper--at least then the issue is isolated to one side

B replacing the bearings might mean that the disk no longer "slaps" the pads back -I doubt it but if thats the case then piston clean up / fresh fluid time and all will be back to spongyness

spacers only fit one way around otherwise the right disc hits the fork

last week when problem occured I tried removing one caliper and drag was lessened, remove both and spins fine. push pistons a fair way back, hoping any shit in the valving would be forced out, put back on, pumped back up and problem remains

old bearings were only just getting grumbly, no play had developed, but i think the right disc did make a chafing noise like it wasn't straight

maybe if the bearings aren't installed properly it would change things, but i always assumed the pressures equalise so provided it's straight the disc can sit anywhere and not have troubles till a piston pops out

so will try for leg, tomorrow night, and see if it works.
then bleed & clean brakes anyway as it needs doing

**motorbyclist** · 3rd July 2008, 23:25

right, so today when i jacked the bike up the front wheel seemed to have finally begun to magically fix itself

(done 800km since wheel bearings installed)

but i thought i'd look at 'fixing' it anyway. re-fitted axle and sure enough i had put it thru just too far by just a smidgeon (not quite 1 mm). at this point i was back to square one as wheel hardly moved.
removed right caliper and left one still dragged but wheel easier to turn than before. swapped calipers and same result

so now i had the left one loose, i went about removing pads and cleaning each piston individually. they all had a fair bit of crap on them, some of which i couldn't move, but they all were clean past a certain point.

remove right caliper (so no brakes) and wheel spins fine - right disc has the slightest of wavers to it, which i already had detected by sound after my little oopsie in movember, but never gave any physical feedback under braking.

all good, reattach left caliper, slightly more drag than expected but bearable

.

right caliper cleaning same as before but couldn't eject one of the bigger pistons, ended up putting tools in caliper to hold the other 3 still while the sticky piston was free, after a couple of pumps the lever was really pushing back, and then with a crack the lever came back to the bar as the piston moved forward. cleaned up piston best i could and it was farking difficult to push back in. reattach, wheel now hard to spin, just like it was before when problem first arised.

so, another 800km and hopefully it'll come right again

actually, after a 50km test in the rain it's not too bad right now, but right caliper is definitely the problem (can tell as it jams more when disc waver pushes against stuck piston)

so i'll make an order for a seal kit and do it properly asap

cheers guys

(PS, where can i get some grease to protect the new seals, and some grease to keep the locking pins from seizing in there? i gather that "normal" grease would not suit)

**imdying** · 4th July 2008, 07:58

Just the act of freeing up the pistons themselves will be worth while

There's no grease that will protect the seals, that's why regular maintenance is important. You can get rubber grease from a brake show to aid assembly, but in reality brake fluid will do that fine. Whilst you're at the brake shop, get a little brake grease (something like Wurth Brake Paste, Girling Brake Grease, or Coppaslip) and use that on your locking pin threads.

**vifferman** · 4th July 2008, 12:29

Originally Posted by FROSTY

Dude think this through.
Brakes were all good-no issues
Wheel taken out -nothin else disturbed
Wheel put back in -brakes suddenly shite

Hmmmm... that sounds familiar.
I thought no-one read the shite I post...

**FROSTY:Me** · 4th July 2008, 18:30

Brakes+ grease/oil = bad

Mate if ya got the time/inclination bring the beast to my place tomorrow.
I suspect Ill be able to clean those pistons up just a "tadd" more'n you did.
Hey did ya try spinning the axle?
Wonder if its got a lil bend in it

**motorbyclist** · 4th July 2008, 23:47

Originally Posted by FROSTY

Brakes+ grease/oil = bad

Mate if ya got the time/inclination bring the beast to my place tomorrow.
I suspect Ill be able to clean those pistons up just a "tadd" more'n you did.
Hey did ya try spinning the axle?
Wonder if its got a lil bend in it

yeah, i was pretty lax on the cleaning - didn't want to use anything harsher than a soft brass wirebrush and there was some stuff that simply wouldn't shift

brakes have made a definite improvement since before cleaning them

slight drag, but it's basically smooth so not a (major) hazard under emergency braking

will pop by if i can