Front Caliper Nightmare!!

[deleted111]

Afternoon, chaps.

A recent incident involving my front wheel eating my front mudguard at speed has left me needing a new one.

I've ordered the mudguard and paint etc... But to fit it properly I needed to remove the front wheel.

No sweat, no centre stand so a bit of support and the use of Warped's chain block has seen my bike into the air for removal of said wheel.

"Wonderful," I thought after removing the wheel, "This'll give me a chance to check the wear on the brake pads and see how these caliper thingies work..."

Well. Took the wheel out, left the caliper on the bike.

Problem I now have, is that I tripped over my tool box when I stood up! I grabbed the first thing I could, which just happened to be my front brake lever.

Caliper's pistony things are now right out, leaving no space whatsoever to refit the wheel with disc!!

I have not the ability to bleed brakes or whatever, is there anyway I can push the pistons back????

Many thanks guys,

Steve.

[devojunior]

calm down and step away from the bike. go find a fairly big flat screw driver and pry the pads apart.

if this fails take the pads out and use a G clamp on the caliper pistons these are the round parts about the size of a 2p coin behind yur pads just simply use the G clamp to wind them back in then relax jobs done.

[BigGeeking]

as long as the seal has not come out the caliper and no fluid has got out they will go back in just take the opportunity to clean the pistons but they can be a arse to get back in.

when all fitted just make sure they work correctly .
all the best
____________________
Bendy "Flip front. I can filter down the M4 while shoving a Twix in my face."
honda CG 125 2001 SOLD-- current Bandit 400--SOLD. current SV650s 2000
MOD 1 ON 20/7/2011**passed** MOD 2 ON 17/10/2011***passed***,,

[deleted111]

I have not a G clamp. B*llocks.

Anything else likely to work? I've never seen one of these newfangled disc brake thingies before, close up. I thought the drum brakes of the CG were hard work

so a G clamp, or mole grips or somethin'?

Cheers for the fast response chap.

Steve.

[deleted111]

[Kickstart]

Hi

You can push them back. However might be a good time to clean them a bit. Take the pads out and use a bit of brake cleaner and a tooth brush.

You can push the piston in with a G clamp, or large pliers. Be careful as if you push one piston in the other will tend to come out a bit. Also be careful that if you take the reservior cap off then fluid will come out of it like a fountain when you push the pistons back. It will spray over things and is a good paint stripper.

You might also be able to use a flat bladed screw driver between the back of the pads and the pistons to push the piston back in. Bit of abuse to the screw driver.

Make sure you push the pistons back in straight.

All the best

Keith
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[deleted111]

Cheers.

I've just been outside, Little piston went back in no problem but the big one won't shift for love nor money! I've taken the brake pads out and cleaned the pistons and back of pads.

Got a big pair of mole grips on the little piston, slowly pushed it (straight) back in. So that's 50% of the piston problem sorted.

This big one just doesn't want to play ball. It's beyond my strength with the molegrips so I'm guessing a G clamp really is the only sodding way to do it??

Bugger.

[Kickstart]

Hi

I would expect it isn't quite straight and is catching on the grooves the seals sit in.

Clamp the little piston in place and then pull the brake lever a tiny bit. Just to move the piston out a fraction of a mm. Then try pushing the large piston back in again.

All the best

Keith
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[deleted111]

Not even a sniff of success.

Definitely need a G Clamp, Mole grips barely grasp the edge, the piston is out that far!

and it really is beyond me to try push it back in bare handed. Which I assume it should be...


Will ask around and see what I can source. Can't afford to buy one until next week at the earliest. Shame. All because of me losing my sodding footing.

Cheers again!

Steve.

[jimbothe]

Have you removed the brake reservoir cap?
I can't see any mention that you have actually removed it.
To stop it squirting you can just lay a clean towel over the top, doubled over and move the pistons in slowly.

It may be why you are having trouble getting the big one in.

Could even be the perfect opportunity to drain the fluid and replace it if it hasn't been done for a while.
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[deleted111]

Cracking idea Jim, I've just been out to try it but no luck.

Took the lid off, laid towel over, piston jammed solid. Now, maybe I'm just ridiculously feeble, I don't know.

I'm going to have to try source a G Clamp from somewhere, then drain and replace all the fluids.

What a PITA.

[jimbothe]

Sounds like there is some resistance. I would shy away from 'forcing' it back in with a g clamp until you're sure there are no obstructions and it is in straight. They are designed to be a tight fit but from what you're describing it sounds like there may be some wear or foreign objects in the way.

It's always better to be safe than sorry. I would be tempted to pull them out and check for any wear markings and it will also be a good chance to check the seals themselves.
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[deleted111]

How would I go about removing them? Pump the brake until they pretty much are ready to fall out?

Little one moves but the big one appears rock solid.

[jimbothe]

Clamp the little one in place and pump the brakes and the big one 'should' pop out but do it over a bucket with towels around as it can pop out with a bit of force.

It sounds like the little one is free and ready to come out so I would concentrate on the big one first.
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[deleted111]

Alright cracking, cheers. I'll set to work on it tomorrow and spend the majority of the day on it until I'm satisfied it's right. Want it sorted ready for going back to work on monday

Cheers,

[jimbothe]

Can you see any visible pitting on the large piston? Would look like little rust spots and in severe cases you can feel a noticeable indentation with your nail.

It may be an idea to source out a rebuild kit before you strip it down as it will probably need new seals.
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[deleted111]

Couldn't see any pitting whatsoever, if I'm honest. Looked in really good nick and IIRC they were one of the things done not long before I bought the bike.

I mean this is all just a daft mistake - I stood up too quick.

Took the wheel out, fine, no problem.

Stood up, lost balance, tripped over aforementioned toolbox and inadvertently twatted the front brake lever, obviously right back to the throttle grip, causing the pistons to come out, pushing the pads together.

From there I had a wiggle about and the pads came off, so they need to go back on also.

Got the small piston in but the big b*stard doesn't want to play ball. So this is my only issue.

Haven't tried anything other than brute force with fingers and thumbs (to no avail) and a crappy pair of mole grips. So will make sure they're in good nick tomorrow along with checking the seals, then perhaps try a G Clamp if I can get my mitts on one.

Appreciate the help,

Steve.

[deleted111]

Progress? Or another barrier?

Sourced some G Clamps from dearest Warped.

Pushed my pistons back in, boo ya! Job done.

Or so I thought...

...Now how the bloody hell do I refit the brake pads?!?!

The big one seems easy enough, as it hooks over them thingymajigs.

but that smaller brake pad, how, what?

gah.


Thanks BCF!

Steve.

[calyx]

Pound shops (everything shops) sell g clamps for peanuts. (if you wanna go that way)

Why don't you just remove the piston and clean everything? (i.e all the gunk behind the seals.)
The only thing you need is a small bottle of dot4 and a towel.
____________________
Boris - London

[deleted111]

I've done that now, Calyx. Got DOT 4, Got a towel. But the pistons are back in now

Just struggling to refit number 1 brake pad

[deleted111]

Please see attached images.

Since then I have placed the caliper back on the bike and refitted the brake pad that has the hoopy bits.

So now, all I'm left with is one brake pad and an odd shaped little clip type thing? I've refitted the big metaly bit.

Any ideas? Many thanks guys.

[Kickstart]

Hi

Not 100% sure as not got one here to double check.

The pad is held in place but sitting in cutouts in the caliper carrier. The small metal clip probably sits flat on caliper. The large one I am not sure about.

Suspect if you put the caliper back on its carrier it should be fairly obvious how it all goes together.

All the best

Keith
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[deleted111]

Thanks Keith, Jimbo, etc!

For those interested, I've managed to complete the caliper and refit to bike.

It's a floating caliper, whatever one of those is? Having looked at diagrams it does appear different to a few others I've seen.

I've learnt alot about these disc brakes over the span of a few days.

The little clip was a retaining clip which slots in beside the smaller brake pad to stop it falling out, basically fills the gap.

and yes Keith, having put it back on the carrier it made a hell of a lot more sense as to how it all goes together.

And at the very least, I can walk away from my toolbox-trippage incident safe in the knowledge that when I need to change my brake pads, I know how to!



Cheers again fellas,

Steve.

[Kickstart]

Hi

Glad you got it sorted. Sliding calipers like that are nice and easy to work on, but do tend to have a few extra clips floating around to confuse you.

All the best

Keith
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[jimbothe]

Nice one mate. Glad you got it all sorted ok.
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