100% Biker & Trike Magazine Forums

Go Back   100% Biker & Trike Magazine Forums > 100% Biker > The Workshop

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 30-11-2007, 11:17 AM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Default Front caliper pistons seized

anyone know the best way to get the pistons out of my brake calipers without a compressed air line? I realise now why my front brakes have been a bit crap recently!
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org

Last edited by Mitch; 30-11-2007 at 11:41 AM.
Reply With Quote
  #2  
Old 30-11-2007, 11:41 AM
Kylie's Avatar
Kylie Kylie is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: May 2006
Location: Morley (50 yrs behind the times)
Posts: 7,425
Send a message via MSN to Kylie
Default

I had to keep working mine from the lever, using clamps to hold in the pistons which would move and keep on and on and on and ... you get the idea until another one moved. They all eventually moved, then when they were far enough out to grab hold of split the caliper and use mole grips and tyre levers to get the barstewards out
Reply With Quote
  #3  
Old 30-11-2007, 11:44 AM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Default

Thankfully, they're only single piston calipers.

Cheers Kylie, I might have to take the stilsons to'em once this soddin' drizzle stops! (typical, eh? Three days off work and it's done nowt but rain!)
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org
Reply With Quote
  #4  
Old 30-11-2007, 12:19 PM
Zaphod Zaphod is offline
Chatter Box
 
Join Date: Nov 2005
Location: Middle Earth Brummagem
Posts: 304
Default

i found that i needed to pump the lever and use a pipe clamp to get my pistons out ...
1. pull lever then clamp pipe..
2. take another pump on the lever , release clamp and re-apply ....
keep repeating and you'll build enough pressure to get the piston to move
__________________
I only post so i can look at the firm bits again
Reply With Quote
  #5  
Old 30-11-2007, 12:20 PM
Kylie's Avatar
Kylie Kylie is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: May 2006
Location: Morley (50 yrs behind the times)
Posts: 7,425
Send a message via MSN to Kylie
Default

Mine have 2 on each side, and 2 calipers on the front - and they were both bolloxed - was sick of the sight of them by the time i'd got the pistons out!

I'll swap you - your piston unsticking for my cleaning, tidying and generally parent-proofing my house......
Reply With Quote
  #6  
Old 30-11-2007, 12:55 PM
madastoast's Avatar
madastoast madastoast is offline
It's about time I shut the fuck up!
 
Join Date: Oct 2004
Location: CLOSED:back in 5 mins
Posts: 1,617
Send a message via MSN to madastoast Send a message via Yahoo to madastoast
Default

In the past I've forced them in and then pumped the lever to push them back out again until they come forward enogh to grip and pull out.
__________________
I BE ME I BE

Faster than an Iraqi window shopper
Reply With Quote
  #7  
Old 30-11-2007, 01:39 PM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Default

I would assume that'd only work when there's some fluid in the system...?

That's the thing, I've been a bit remiss over the past few years with that bike. I've only ever changed the fluid once and that was a few years ago - when we lived in Horsham (so that must be at least four then )

The right hand side piston's popped out - however, the left one (the one that'd been causing the trouble) is stuck fast. Can't get it past the groove at the top.

Is it worth putting more fluid into the line? Obviously, I'd need to clamp the right hand side brake line so I don't get anymore fluid anywhere (I suppose); or is it better to use an airline?
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org
Reply With Quote
  #8  
Old 30-11-2007, 01:48 PM
madastoast's Avatar
madastoast madastoast is offline
It's about time I shut the fuck up!
 
Join Date: Oct 2004
Location: CLOSED:back in 5 mins
Posts: 1,617
Send a message via MSN to madastoast Send a message via Yahoo to madastoast
Default

As I understand it (not being an expert) hydraulics and pnuematics are related but not the same. I would think that you couldn't build up the correct pressure with an airline ( see why women don't fart) because of air escaping as you're trying to blow it out.
__________________
I BE ME I BE

Faster than an Iraqi window shopper
Reply With Quote
  #9  
Old 30-11-2007, 03:09 PM
colin colin is offline
Need to Get out More!
 
Join Date: Sep 2004
Location: North Devon
Posts: 476
Default

Mitch,

Bring it round here and i'll have a go - what you have to ask yourself is: are you planning to replace the piston - if yes then a pair of molegrips or such like on the piston with someone holding it and then large amounts of air in the hole where the banjo bolt screws in, then keep pulling and blowing!!
__________________
I'm a peaceful person who just happens to be filled with violent rage.
Reply With Quote
  #10  
Old 30-11-2007, 03:28 PM
Borg's Avatar
Borg Borg is offline
Banned
 
Join Date: Jun 2004
Location: The Independent State Of West Wales
Posts: 4,521
Send a message via MSN to Borg
Default

Or stick a grease nipple in the bleed nipple hole and use a grease gun
Reply With Quote
  #11  
Old 30-11-2007, 04:50 PM
noisygit noisygit is offline
Jedi Chat Master
 
Join Date: Feb 2005
Posts: 617
Default

Since one piston is out I'd disconnect the brake lines then reassemble so that you've only got the offending caliper connected to the master cylinder. Top up with brake fluid then try pumping the piston out, if it still doesn't move then pushing it back in with a g-clamp or similar may help crack the piston loose. Hope this makes sense, I'm finding it difficult to explain just what I mean.
Personally I wouldn't try clamping the pipe as I think it may bugger the pipe up unless you're going to change the brake lines then it won't matter.
Reply With Quote
  #12  
Old 30-11-2007, 05:01 PM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Default

Good plan! Thanks for that Noizy Git! I shall try that (means going out and getting some more brake fluid - next question... what dot rating do folks reckon (because you can no longer get the stuff in the manual from halfords or wherever)?
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org
Reply With Quote
  #13  
Old 30-11-2007, 05:07 PM
Kylie's Avatar
Kylie Kylie is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: May 2006
Location: Morley (50 yrs behind the times)
Posts: 7,425
Send a message via MSN to Kylie
Default

Dot 4

.......
Reply With Quote
  #14  
Old 30-11-2007, 05:58 PM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Default

Shouldn't that be .... not ....... then? :Snigger!:

Damn, we could do with a snigger smilie on here!!

Thought so. That's what I bought last time when I sorted out Mrs R's brakes. I thought I had some left somewhere, sadly, it's not to be!
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org

Last edited by Mitch; 30-11-2007 at 06:03 PM.
Reply With Quote
  #15  
Old 30-11-2007, 06:15 PM
Kylie's Avatar
Kylie Kylie is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: May 2006
Location: Morley (50 yrs behind the times)
Posts: 7,425
Send a message via MSN to Kylie
Default

Quote:
Originally Posted by Mitch
Shouldn't that be .... not ....... then? :Snigger!:

Damn, we could do with a snigger smilie on here!!

Thought so. That's what I bought last time when I sorted out Mrs R's brakes. I thought I had some left somewhere, sadly, it's not to be!
It would be running the risk of having attracted water by now and wouldnt achieve the same pressure as new stuff (see Grav I was listening!)

I have a bottle under the sink thats not too old, but its not much help to you!

And as for the dots... bloody 10 character minimum post gets on my nerves
Reply With Quote
  #16  
Old 03-12-2007, 02:19 PM
contail's Avatar
contail contail is offline
Banned
 
Join Date: Sep 2005
Location: East sussex
Posts: 1,129
Default

i got some dot 4 you can have. just done my siezed brakes. dont think im far from you. working nights though. prob can meet you some where on a21.
Reply With Quote
  #17  
Old 03-12-2007, 05:06 PM
trikerdrew's Avatar
trikerdrew trikerdrew is offline
It's about time I shut the fuck up!
 
Join Date: Dec 2004
Location: leicester
Posts: 1,994
Talking attack depends on what your keeping!

HI Mitch,

Depends largely if the piston is fubarred.If so and you have tried pumping it etc.........

If yes,brute force!!Drop in bucket of hot water.Go have a brew.Put caliper mounting point in vice.Boa grip on piston should turn it,failing that as suggested before(cringe )stilsons.

Not enough to grip a problem?Weld big nut on bottom-that'll turn it esp. while it is hot.

Pistons can be turned in stainless that stops this happening.Seem to remember pricing kwak parts up and bursting into tears once I'd realised they wern't joking.Worth pricing up first as could be economically more viable to replace.

Drew

Oh aye.If you find someone who can do stainless at a good price let me know,pretty please!
__________________
"All I learnt at school was how to bend and break the rules",Madness
Reply With Quote
  #18  
Old 03-12-2007, 05:28 PM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Default

Quote:
Originally Posted by contail
i got some dot 4 you can have. just done my siezed brakes. dont think im far from you. working nights though. prob can meet you some where on a21.
Cheers for the offer mate, but got some!

Drew... what are you like? Mate of mine's got a compressor and he's going to sort it.
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org
Reply With Quote
  #19  
Old 03-12-2007, 06:53 PM
Zaphod Zaphod is offline
Chatter Box
 
Join Date: Nov 2005
Location: Middle Earth Brummagem
Posts: 304
Default

be extremly careful using a compressor to remove the piston, it'll possibly be a little like a very short barrelled air rifle when the piston lets go, as once it starts to move air will just keep pouring in and the piston will most likely start accellerating ....

i'd still prefer to remove it using the pump and clamp method i outlined earlier (use scrap hoses if needs be)
__________________
I only post so i can look at the firm bits again
Reply With Quote
  #20  
Old 03-12-2007, 07:23 PM
noisygit noisygit is offline
Jedi Chat Master
 
Join Date: Feb 2005
Posts: 617
Default

This is not a method I'd recomend but I once used a bloody great machine that was like the mother of all grease guns, it was meant to provide constant lubrication to all the grease points on a whole assembly line. We bodged up a connection to my caliper and fired it up, nothing seemed to happen at first so my mate suggested I give the caliper a little tap with a mallet. We never did find the piston and fortunately the boss never found out who was responsible for all the grease that covered everything in the vicinity
Reply With Quote
  #21  
Old 05-12-2007, 11:38 AM
trikerdrew's Avatar
trikerdrew trikerdrew is offline
It's about time I shut the fuck up!
 
Join Date: Dec 2004
Location: leicester
Posts: 1,994
Default ho,ho,ho

I got hacked off with a caliper.

Cannot believe this sounded like a good idea

sealed one end up.Filled with water.Sealed top.

So far so good!

Left a butane tourch on it.

Went to local shop for drinkies.

Got back -oops.Piston had shot out phooked up a tank I'd painted day before.

Oh joy,i thoght as I went skipping away from workshop.

Drew
__________________
"All I learnt at school was how to bend and break the rules",Madness
Reply With Quote
  #22  
Old 05-12-2007, 12:10 PM
Gregg1100 Gregg1100 is offline
Chatter Box
 
Join Date: Sep 2005
Location: South Wales
Posts: 370
Send a message via AIM to Gregg1100
Default Front caliper pistons seized

Hi All,
This has always worked for me. Get a car tyre valve-insert it in car/bike air pump end---make sure bleed nipple is still tight, and whilst holding the rounded end of tyre valve onto calliper hose inlet, pump foot down on pump. Piston will pop out. Dont have fingers anywhere near the area where pads go, or you will be popping to casualty.
Greg
Reply With Quote
  #23  
Old 06-12-2007, 08:24 AM
trikerdrew's Avatar
trikerdrew trikerdrew is offline
It's about time I shut the fuck up!
 
Join Date: Dec 2004
Location: leicester
Posts: 1,994
Question how do Mitch

What happened to the caliper in the end then?

Did you rip a branch off a tree and whip it into submission a la John Cleese?

Nosey sod ain't I

Drew
__________________
"All I learnt at school was how to bend and break the rules",Madness
Reply With Quote
  #24  
Old 12-12-2007, 10:50 AM
greg greg is offline
Jedi Chat Master
 
Join Date: Oct 2004
Location: south wales
Posts: 734
Default

had the same problem with my old xs1100 used a air line to pop it out keep the bleed nipple done up and hold the caliper in a vice work bench ect but keep the piston pointing away from you and aim it at a old towel /rags ect to catch it.
apply the air and keep the air going in and watch the piston when you see it start to move use trigger motion on the air gun to push it out in a more controlled manner when its over half way out let of the air and try to pull it out or in my case just keep pumping the air till it pops out
be ware it can go off like a bullet first time i did it i shot the other side of the shed.
use the pistol type of air gun the point fits loverly into the fluid inlet.

good luck
Reply With Quote
  #25  
Old 27-12-2007, 03:17 PM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Talking not been on here for a while, can't you tell?

Finally had the time to sort this caliper out.
A mate of mine at work tried with an airline and got nowhere... at least he had a go.

Just been out there today, seeing as Mrs R's at work, I've got a bit of time on my hands as I don't go back to work until the 2nd. I ended up connecting the caliper onto the first line which normally goes to the splitter as per noizy git's idea above. I had to then bleed the damned thing as there was loads of air in the line, putting brake fluid into the master cylinder as I went.

All of a sudden, the piston popped out quite nicely.

Question remains... should I just clean the old pistons or get new ones?
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org
Reply With Quote
  #26  
Old 27-12-2007, 04:41 PM
Dougie's Avatar
Dougie Dougie is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Jul 2004
Location: In the canyons of my mind.....
Posts: 19,609
Default

Are they corroded or just manky?
__________________
We will remember them.
Reply With Quote
  #27  
Old 27-12-2007, 05:20 PM
Taff's Avatar
Taff Taff is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: May 2005
Location: Yorkshire
Posts: 4,954
Default

I always found on calipers that the main culprit is the bit what the piston seal fits in, in the caliper itself.
Poke the usually square section seal out, and clean all the corroded ally out the channel it sits in, first with the short end of an allen key, cos it's okkerd to get to, then with steel wool or summat. That corrosion can push the seal onto the piston dead tight when it all looks nice and clean from just a quick look.
Reply With Quote
  #28  
Old 27-12-2007, 07:29 PM
Mitch's Avatar
Mitch Mitch is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Apr 2004
Location: Between the Sea and the South Downs
Posts: 4,802
Default

Quote:
Originally Posted by Dougie
Are they corroded or just manky?
The ends are a bit brown, from where the disks went a bit rusty (trouble with the bike being outside) but the rest of them are just a bit manky to be honest.

I'm going to attack the disks with scotchbrite to get all the rust off - should do the trick.
__________________
Grav says: "...It never fuckin' ends......... "

Switch off TV, get a life... www.whitedot.org
Reply With Quote
  #29  
Old 27-12-2007, 07:44 PM
Dougie's Avatar
Dougie Dougie is offline
Talk, Type, Breath, Talk, Type, Breath....
 
Join Date: Jul 2004
Location: In the canyons of my mind.....
Posts: 19,609
Default

Give the pistons a good clean then a polish with Solvol or the like.As Taff sez the groove for the seal may need a bloody good clean,so yer as well fitting new seals while yer at it.As for cleaning up the discs,you'll do that the first time you apply the brakes!
__________________
We will remember them.
Reply With Quote
  #30  
Old 27-12-2007, 08:09 PM
Borg's Avatar
Borg Borg is offline
Banned
 
Join Date: Jun 2004
Location: The Independent State Of West Wales
Posts: 4,521
Send a message via MSN to Borg
Default

Quote:
Originally Posted by Mitch

Question remains... should I just clean the old pistons or get new ones?

Is your life worth 20 or so ?
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 02:44 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.