Rear brake pads

[Rookie]

Right, I'm halfway through changing my rear brake pads, and need a speedy answer, if that's OK.

Basically, I've got the old pads out (they were down to the metal, and were binding considerably, it took about 5 minutes with needle nosed pliers to get them both out) and now I'm stuck. The master cylinder (or whatever it's called, the one that moves against the pads) is too close to the brake disc. In fact, it's pretty much against the disc. I've attached a high-res photo of the problem. It may be that close to the disc now because I, being the fool I am, pumped the rear brake lever a few times in an attempt to free up the problem.

What do I need to do to free it up and get it away from the disc, so I can slot the new pads in?

All advice gratefully received.

[DanceLikeAMon...]

Firstly, take the caliper off so that you can access top and bottom, and start scrubbing the pistons with brake fluid and a tooth brush, until you get all that crap off them.

The pistons on mine are so stiff that to get mine to go back in I need to put a spanner across them and force them back inside. Once you've done this, it'll be worth working them back and forwards a bit until they move a little easier, then force them all the way back and slide the pads in.

Here is a crappy pic to show what I mean. Put both thumbs wherer the pink dot is, and a hand either end of the spanner, then pull until your biceps pop or the piston moves, whichever comes first. Make sure that the other piston doesn't get forced out while your doing this.
https://img.photobucket.com/albums/v158/dance_like_a_monkey/crappy_pic.jpg

[McGee]

Just been telling him in msn the same, which sucks because if I was him I would not wanna take any thing apart
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◙◙► K6 GSXR 600 ◄◙◙◙◙► K5 GSXR 1000 ◄◙◙◙◙► K5 GSXR 600 ◄◙◙◙◙► 96 RF600r ◄◙◙
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Its pronounced Jixxer!

[Phil_G]

Hiya

THe way Ive done it in the past on cars is to use a G clamp or a clamp of somesort with an old pad and then put the old pad over the piston, and then tighten the clamp over the pad and the back fo the caliper and use that to push the piston back in.


good luck with it either way
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1997 Kawasaki ER 500 A1:- Once again, Its merely crap

[NSR Mick]

Those pistons look short of a damn good clean, on a similar note I changed the front pads on my nsr yeterday in the yard of the mot station to save time getting a retest in under 15min.
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If you dont like the way that I ride.......Stop trying to keep up!!!

[Nath]

Yup, lever them back in with a screwdriver, or use a g-clamp/adjustable-pliers to force em in.

To protect your pistons you can stick the old pads in and push against them rather than the pistons themselves. If you use a g-clamp or similar, be careful you don't damage the soft alloy caliper.
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Hard livin', hard luck.

[DanceLikeAMon...]

Unfortunately, his rear caliper looks the same size as mine which means that there isn't a G-clamp with a small enough head to fit in there unless both pistons are most of the way back (which kind of defeats the purpose ).

If anyone knows of a clamp with a small thin head that can exert enough pressure to push pistons back in, I would be really grateful 'coz it would save me a load of strain next time I change my rear pads.

[NSR Mick]

If you cant prise them back with a screwdriver without thinking your gonna break something they could probably do with a strip and a clean.
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If you dont like the way that I ride.......Stop trying to keep up!!!

[Guest]

What they ^ all said


If you've topped up the master cylinder recently you'll have to drop the level a bit, as when you force the pistons back it'll push fluid back up into it. I use a clean spoon or a plastic syringe.

[Whosthedaddy]

[Rookie]

Done, finally! I got the caliper off, gave it a scrub with brake fluid, then spent the next 45 minutes (literally) pushing the pistons back in. Every time I got them in a bit furhter, some fluid came out the bit that attaches the piston to the lines. Is that right?

I then refitted it, slapped the new pads in (tight fit! ) reassembled it and topped up the brake fluid. I'll go run them in tonight before the big run tomorrow, hopefully they'll be OK and won't bind like before otherwise May Day might be out of the question, and I'll have to totally strip down the caliper again too.

Thanks for all your help guys.

[numark1]

What do you mean piston to the lines?? If you mean seal then its leaking and they seals are probably wrecked. The brake should be ok short term (using front brakes is fine) It could be the actual pison seals leaking not the dust seals. Either way new seals are £££

My zx6r seals cost about £70 (that was for front though and 6 pot calipers)

Might be worth sourcing a new rear caliper.

[Rookie]

No, I meant from the bolt where you attach the brake line. So the pots were filled with fluid, but when I pushed the pistons back in it forced fluid out that line bolt.

I'm considering a new caliper anyway tbh, the bastard is so seized up I'll pop the pistons out next week, see if I can get them going again. But if I need new seals anyway... crikey.

[numark1]

I see leaking from the banjo bolt.

Did you undo the bolt/take it off? There should be a copper washer with the bolt. If its not there then that is probably why its leaking.

[Nath]

You mean the banjo. Is the fluid coming from where the brake line attaches to the banjo, or from the bolt that goes through the banjo?

That is most definitely not right.
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Hard livin', hard luck.

[Rookie]

After a chat with Mark, it seems I'm missing a copper washer from the banjo bolt, which is why the pistons were leaking out through there. They shouldn't have been moving at all really, I'd completely left out the proper bleeding blots on top of the caliper.

I'll start scouring eBay for a new caliper, as I really don't want to shell out £££ for new seals for a caliper that doesn't even want to work properly.