Bugger *brake caliper maintanence*

[killa]

I know this should go in workshop, but I’m going home soon and might need to pick up bits. Plus I’ve never done this before….

The pistons on the ZX7R callipers (6 pot tokio things) are seizing, she didn’t enjoy the rain last night and now they are stuck.

So I take the callipers off……now what

I’m going past the bike shop on the way home so if I need any consumables, please let me know.

Thanks in advance

Killa
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[T1z3R]

unbolt the calipers and pump the pistons out a bit and give them a good scrub with brake cleaner and a toothbursh. also inspect them for wear/tear that might damage the seals. push the pistons back in if they look ok and test them out. if the problem persists then it might be time for new seals and/or pistons.
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duck my sick!

[killa]

I was told you can ruin the seals if they come out too much, would they need to be stupidly far out for this to happen?

Do i need to take the cap of the bottle at the handle bars?

Thanks for the advice, i've seen it being done, just not on mine.

Edit: - also, do i need to put any type of grease on the pistons before they go back in?
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[johnsilva]

Take the pistons all the way out and buy some new seals!

Wemoto do a kit for £50 - i replaced all mine last week.

Pistons were pretty disgusting - but they cleaned up nicely, and with a bit of grease, they went in sooooo nicely!

Fresh pads too. and get a brembo master cyl.
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[Whosthedaddy]

Seals were leaking on one side and seizing on the other so everything taken out and replaced. Cost me £170 for the garage to do it.

May be of some use:

https://www.bikechatforums.com/viewtopic.php?t=63228
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Current : MSX 125 Past : CBR 900RR Monkeybike : c50 LAC : ZXR750 H2 : FZR600 : ZX7R P3 : YW100 : TRX850: Trophy 900 T309 : GSXR 600 L0: Monkeybike : XJ6S Whosthedaddy

[killa]

Errr mine really aren't that bad! wow, those look a total mess

Im going to give cleaning them up a go first before the seal kit.
If i split them then i will have to bleed the whole system again.
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[Whosthedaddy]

[T1z3R]

yeah i wouldnt pump them too far out...just far enough that you can see where the crud stops. youll probably take the cap of the master cylinder anyway to top the fluid up a bit. dont grease the pistons just apply some fresh brake fluid
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duck my sick!

[killa]

Ok, i took the advice and got craking.

Got the caliper off, using all kinds of weird and wonderful ways with the tools i had, i got each piston out as far as i thought ok and cleaned.
All of them look clean now, i have a hard job putting some back in and not others. With a little lube, i got them back in.

So...

I was thinking, they should all slowly come out when i pull the lever yeah?

Because they don't. Now im thinking the worst, they are bolloxed.
The old man says if they dont come out together then you get un-even braking, which makes sense, but do they really need to be so spot on?

So whats the next plan? Full set of seal and a total strip down?

Thanks guys
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[alun111]

When you fitted the caliper back to the disk did you pump the lever several times to put the pads back in contact with the disk? All the pistons should come out and touch the pads if so.
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[Phoenix]

The pistons will hardly ever all come out at equal speed when you pull the lever, more noticeable on 6 pots than 4, plus the pistons are different sizes. When I clean them, I clean them all individually and keep pushing them in and pumping them back out individually until they move with relative ease, can take a while, if the seals are screwed it'll never happen.

Brakes are something you need to keep ontop of, especially on those calipers, I cleaned my GSXR750 6pots 2 or 3 times a year to prevent them ever siezing and do the Blade a couple of times, because siezed calipers really are a pain in the ass to sort out.

I've never understood why they don't fit some kind of rubber gator over the pistons like they use on car calipers, would be perfectly possible to do even given the smaller size, maybe they just don't want to promote lack of maintenance on motorcycle brakes.

[DEN MONKEY]

I got bored on the weekend and pulled my front ones off. I didn't disconnect em just took the pads out for a look see and a general clean.
I had some crap on mine but managed to get most of it off for a future pad change.

I was thinking they were bad until I saw those pics. Dude those are fucking terrible.

How come we don't get to see an after pic

Was considering a new set of seals too but was hoping to get through a pad change without having to bleed the system although a change of fluid could be in order too I guess.
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meh

[johnsilva]

[killa]

This is the discussion i had with my old man about them, this is why i stopped doing the job...

I had them looking clean on one side, all of them can come out but you have to hold one with your hand. It doesn't take much. I was trying to explain to my dad that if any vehicle has done over 10K on the clock, without regular maintanence you wouldn't get pistons coming out simultaniously when you pull the lever.

So do i carry on what im doing, i got them looking a lot better. Why is it incredibly difficult to get certain pistons in when they seem to come out ok. ?

Thanks again people.
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[T1z3R]

if your happy that they are clean the remount the caliper and tighten everything back up then bleed the system or replace the fluid all together then try them out
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duck my sick!

[Bullet]

[killa]

A smigen of WD40 was what they advised me at the garage.

Errr
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[Stelmer]

You should see my caliper.

The small piston was totally rusted to the caliper and the big piston hardly moved. The pads were rusted to the caliper as well.

Took a G Clamp and allot of pumping on the brake lever to get the little piston to move. The big one moved out but was very reluctant to go back in.

Took it to the Garage and got them to clean and replace the seals as there was rust and corrosion under the seals.

[Bullet]

[Bullet]

oh and also when you split the caliper did you replace the small seals where the 2 half's join? if not then do so, your not supposed to reuse them as they're crushed when fitted.
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[killa]

Thanks for the advice Bullet.

I haven't strip them though, only cleaned around the pistons that are exposed.
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[johnsilva]

[Whosthedaddy]

[johnsilva]

[Whosthedaddy]

Any suggestions or easy swaps? Maybe a wrist band around them would help.

I'm no Jeremy Beadle when it comes to having small hands, but would changing the lever size effect the braking. At the moment I have my hands rammed up against the stocks so I'm pulling against the thickest part of the lever rather than a few fingers on the end. It doesn't feel right to have my hands near the bar ends.
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Current : MSX 125 Past : CBR 900RR Monkeybike : c50 LAC : ZXR750 H2 : FZR600 : ZX7R P3 : YW100 : TRX850: Trophy 900 T309 : GSXR 600 L0: Monkeybike : XJ6S Whosthedaddy