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Rear Caliper Help
Posted: Fri Jun 10, 2011 2:46 pm
by iDemonix
Ok so my rear brake has always hardly worked, had to pretty much stand on it to get it to slow me to a stop. Anyway lately it's been binding worse and worse, I raised the wheel off the floor earlier and can hardly spin the wheel with one hand it's that bad. So I whipped out the Haynes and took off the two bolts holding on the rear caliper and removed it. Once off I pushed the rear brake to see if the pads were moving much, they closed up and now I can't unclose them. Should I not have pushed the rear brake with the caliper off the disk? I know NOTHING about brakes.
I'm becoming #1 question asker of this forum.
How can I get the fucking things apart and how do I inspect what's causing the binding?

Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 2:51 pm
by mattUKNC
...this is the old..."whatever you do, don't press the rear brake pedal when you've taken the caliper off" line.
If you can get a screwdriver between the pads you might be able to split them. Then use a proper splitter to push the pistons all the way in.
I've only gone as far as changing pads, never stripped a caliper completely.

I'm sure someone will be along in a minute.

Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:10 pm
by porndoguk
im here, rear brake caliper specialist!
if you prepare to fuck the pads up get a screw driver in and lever them off a little,
once theyre loose youll need to undo the grub screw, then undo the pad retaining pin with a 5mm allen key.
once there out hit the brake pedal to push the pistons out you may need to twist them out by hand,
the rear caliper is a simple thing,
Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:11 pm
by iDemonix
I decided to remove the pads, I love the design of the pad retaining pin, undo a screw to get to the hex bolt - very clever indeed. Anyway, upon inspection, my pads look a bit shot - they're smoother than a baby's arse. Also, what Haynes tells me is the 'Front Pad Spring' has snapped - not by my doing - it was snapped and one of the pads was caught on the piece of metal in the middle of the spring, which was not letting it move properly. I don't understand how they're 'springs' as they just look like flat pieces of metal to me but meh.
So, the spring is fucked, the pads are shot and the pistons aren't returning - how difficult is a full caliper overhaul? I need to use the bike to get to work every day except wednesday and sunday and lifts aren't possible as I start at 6am. If I can't get it sorted for monday I'll just have to ride with no pads in the rear brake (Extremely stupid, but I never use it anyway and even when it had pads it didn't really work).
Are pads and that spring universal? Or am I going to be waiting for some time...

Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:15 pm
by porndoguk
iDemonix wrote:I decided to remove the pads, I love the design of the pad retaining pin, undo a screw to get to the hex bolt - very clever indeed. Anyway, upon inspection, my pads look a bit shot - they're smoother than a baby's arse. Also, what Haynes tells me is the 'Front Pad Spring' has snapped - not by my doing - it was snapped and one of the pads was caught on the piece of metal in the middle of the spring, which was not letting it move properly. I don't understand how they're 'springs' as they just look like flat pieces of metal to me but meh.
So, the spring is fucked, the pads are shot and the pistons aren't returning - how difficult is a full caliper overhaul? I need to use the bike to get to work every day except wednesday and sunday and lifts aren't possible as I start at 6am. If I can't get it sorted for monday I'll just have to ride with no pads in the rear brake (Extremely stupid, but I never use it anyway and even when it had pads it didn't really work).
Are pads and that spring universal? Or am I going to be waiting for some time...

you need to get ordering now so things can be delivered for tommorrow,
pistons can be refurbed but youll need polishing wheels to remove a layer of shit without damaging the chrome plating,
spring may be a special order from DSS
Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:18 pm
by iDemonix
I can see pads on DSS website but not that bloody spring, agh, where's going to stuck such a unique part?

Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:35 pm
by mattUKNC
iDemonix wrote:I can see pads on DSS website but not that bloody spring, agh, where's going to stuck such a unique part?

I have a rear caliper with a snapped bleed nipple, consider the springs yours! I'm popping to the post office tomorrow so pm your address and I'll send them off, I'm guessing you'll need both?!
Matt

Where are you?
Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:42 pm
by iDemonix
You are a leg end. I'll PM you my address now.
I *think* my front spring is ok, but if you're not going to use them I'll happily take both! I'm going to order a new set of pads from DSS too. I just tried to spin my rear wheel, it's easier but it's by no means freely spinning, need to take the rear hub off and grease it to death or new bearings? The stand I'm using goes inside the rear wheel hub (not like an abba frame stand) - the bit that lifts the bike up doesn't spin freely, maybe that's why? Or does the internal of the hub not rotate...
I'm telling you lads, couple of years and I'll be an NC30 mechanical master.
Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:43 pm
by Deviant400
my bike always suffered from this . pop the pistons out and get new seals , really easy to to do , polish up the pistons and use a bit of dot4 to smear over the pistons and pop them back in , refill the system with fresh fluid and bleed , job done and a sweet workin back brake , well worth the little effort needed
Re: Rear Caliper Help
Posted: Fri Jun 10, 2011 3:46 pm
by Deviant400
the bit that lifts the bike up doesn't spin freely, maybe that's why? Or does the internal of the hub not rotate...
put the bike on the side stand and try tilt it over a bit till the wheel comes off the ground and spin the wheel that way you wont have the stand in the hub