View Full Version : Dave request
Need some help and support to convert the thing bolted next to the disc on my scooter into something that may actually do a passing impression of a brake caliper.
Given the recent "why" thread I'm not looking for someone to explain which specific make of red grease I need to be using but someone who can guide me through my first "banjo off" activity given upto now I've limited myself to simple pad replacement/bleeding and of course pivot lubrication activities.
I have tools, brakefluid, a carport, lighting, working kettle and good supply of hob-nobs. (don't have any red grease yet though)
Thunderace
27-08-12, 12:17 PM
Tomorrow evening convenient? Or this afternoon/evening?
You won't need to download a thing, no unicorn blood required, just brake fluid, a socket set and a spanner that fits your bleed nipple! (lol he said nipple)
Don't worry about any grease, your new banjo bolts come with washers and they will seal it fine, and before any of you google happy folks start with the "erm I think you'll find......" nonsense, If you've had banjos leak after replacement you're a limp wristed gayer and need disciplining accordingly!
You will need a left hand screw driver ;)
OK.
1. loosened and re-tightened calliper retaining bolts
2. Loosened banjo and nipped upagain due to emerging fluid but at least I know it's loosenable while still fitted to bike
3. Loosened and re-tightened bells nipple
So-far so good. Mechanical due-diligence completed
4. Removed caliper retaining bolts
5. removed banjo and captured drained fluid in pre-positioned plastic box and last weeks Sunday times
6. Taped plastic bad over banjo to catch anything that may leak
Caliper now on work bench (wheelie bin but does the job) and feeling pretty pleased with myself so-far
7. Removed pads, anti-rattle plates etc so I can get at the piston
8. wondered how to get piston out. Pulled it, pushed it, seized solid as expected. Nothing I can form an airtight seal with so can't blow it out with compressor so no option other than to refit and push it out with brake lever
9. Refit to bike with no pads and 1 caliper bolt. Mrs.H encouraged to come and squeeze when requested.
10. Bled caliper (heinus crime of recirculating the fluid but I plan to change it all when done anyway).
11. Got caliper working again and could push piston out.. Plan was to get it 90% out then take off again.
12. At this point you are imagining piston flew out, everything covered in brake fluid etc but no.......
13. Piston probably 70-80%out but will shift no more. Brakeline in danger of bursting if any more pressure applied. I assume in theory it should come all the way out. Obviously this may be an incorrect assumption.
So question is what do I do now?
a) spray wd40/brake cleaner/brake fluid/unicorn blood or similar into caliper body to free up the piston
b) just cleanup what I can see, push it back and hope it doesn't rip the seals to buggary
c) go buy a new caliper/scooter
Constraints:-
I have no brake spares other than fluid so ideally want to get it better without needing new seals, banjos etc
Thunderace
27-08-12, 02:55 PM
OK.
So question is what do I do now?
a) spray wd40/brake cleaner/brake fluid/unicorn blood or similar into caliper body to free up the piston
b) just cleanup what I can see, push it back and hope it doesn't rip the seals to buggary
c) go buy a new caliper/scooter
Constraints:-
I have no brake spares other than fluid so ideally want to get it better without needing new seals, banjos etc
Hamfisted cowboy/Dave en-route!;)
Spank86
27-08-12, 05:22 PM
3. Loosened and re-tightened bells nipple
only fallout knows why I laughed at this.
Fallout
27-08-12, 06:22 PM
Not funny! :D
Seems Nathan's reputation extends beyond this forum. No sooner had he jumped in his rapid response vehicle to get over the piston threw it's virtual hands in the air and freed up.
As Nathan was here anyway we had a brew, slagged the rest of you off and debated what sort of memorial Fallout was likely to want when the chewing gum holding his bike together finally gives way.
So once left on my own I re-removed the caliper and got to work cleaning it. The piston virtually fell out and the surface damage was largely light and came off with a bit of rag in WD40. Cleaned out the inside of the piston and generally gave it a good check-over. Was in remarkably good condition.
The sliding mechanism was more of a problem but now slides beautifully.
Coated all the surfaces in new brake fluid and started to push the piston back into the caliper expecting it to be silky smooth. It wasn't. Took it out again rechecked the seal was sitting right and everything was super-clean and tried again. Still not good.
But getting dark and I need to use it tomorrow so persuaded gently with a 17mm socket and a rubber mallet and it went in.
Had to bleed it single-handed without one of those fancy single handed bleed kits but if you set it all up right you can reach the brake lever and the 8mm spanner without knocking over the jar of brake fluid. Only thing is you can't see how much fluid is in the reservoir so have to stop and check every 4 squeezes.
Anyway quick ride up and down the road and it is a lot smoother but still not amazing and the wheel is not entirely free so it's still binding a bit.
I'll treat it to some new, soft pads and a new rubber seal at some point and see if the treat shocks it into some performance.
Luckily the rear brake is still superb.
So big thanks out to Nathan for his second mercy dash of the weekend.
Fallout
27-08-12, 08:23 PM
Those pistons are always a bitch to get back in. I was trawling the net for tutorials on how to rebuild callipers a while ago and came across loads of posts from whining babies (much like yourself) saying they couldn't get them back in because their pathetic baby fingers were only good for picking their noses and scratching their balls. So don't worry Mark. Silky smooth aint right. It's supposed to be tighter than Nathan's generosity with cigarettes, otherwise the fluid seal wouldn't be good enough.
Thunderace
27-08-12, 09:39 PM
No probs Mark, felt like a spare wheel once I got to yours and all you had left to do was a bit of cleaning and a refit, definitely go for some new pads, and what did I say about brakes? Lube and a hammer can sort most issues if only temporarily!
Thunderace
27-08-12, 09:42 PM
Silky smooth aint right. It's supposed to be tighter than Nathan's generosity with cigarettes, otherwise the fluid seal wouldn't be good enough.
Oih You! Sorry I mean Prime Minister! I'm not tight with fags its just that Mrs Ace dont like me buyin' 'em!;)
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