Rear brake failure!

[Crap Tartan]

On way to work this morning, the rear brake stopped working.

I carried on and got to work and had a looksee....

No fluid leaks anywhere
no pressure in system, plenty fluid in reservoir
Pedal operates normally
Brake disc looks slightly discoloured as if has been heated?
Caliper and pads look OK

my best guess is master cylinder piston seal has failed but open to any ideas?

[shebee]

We have had a variation on this before here... try the below for suggestions/sympathy/ hints? Im at work so cant go through it properly now xx

http://www.raptorchapter.org.uk/viewtop ... pped#p4251

http://www.raptorchapter.org.uk/viewtop ... ped#p21303

http://www.raptorchapter.org.uk/viewtop ... e+bleeding

HTH

[Crap Tartan]

Yup, had a look thru them, will strip it tonight when I gat home and see what I find?

Thanks Shebee!!

[snapdragon]

little plunger thing come adrift maybe?

[Crap Tartan]

little plunger thing come adrift maybe?

if only it was that simple Snap!!! (i wish!)

anyway got bike home stripped everything to bits and found;

looks like master cylinder is knackered (wouldnt bleed brakes and does not appear to pump fluid to caliper)
there are signs of water corrosion in cylinder but cant get piston out as its stuck!
brake disc looks ok but shows signs of overheating (slightly blued)
stripped caliper and more signs of overheating on pistons and seals.

So anyone know where I can get a replacement master cylinder and a seal kit for the calipers?
plus need all this PDQ so i can be ready for next weekend.........................

[dizzyblonde]

Master cylinder for da rear is shared with

Cagiva Mito/Planet 125

Aprilla Mille of some description

I know the Mito fits, as Matt nicked one off a mates when his went pop. They're cheaper than the other alternative

I have a place called Ducati Mondo that's opened up round the corner from me. If I can get round there, I'll have a wee word and see if he can source one, if you have trouble finding one

[Crap Tartan]

cheers Dizz!

I can get a new MC for around £50 and the cheapest Mito secondhand from a breaker I can find is £30 so would rather just pay the extra and have new (known good)

I would like to replace seals on the caliper so if you can ask at that place, nearly all the italian bikes share that caliper/ piston/seals apparently , even the front opes are same diameter/size etc.

cant seem to find a seal kit anywhere....................................

[dizzyblonde]

Well that's fair enough, may as well buy new for that cost!

https://www.ducatimondo.co.uk/store/

Website, don't look like he has them, but I shall go bend his ear a bit... can't burst his eardrums from my house on the VRap. Its literally on the end of my street is his shop!
He might have some tucked away hes forgotten about

[Crap Tartan]

cheers, if it helps the rear caliper has part nos 6891/6892 (each half of caliper) and there are two seals (oil and dust) for each piston and a piston at each side.

[snapdragon]

if it's the original caliper (knowing your Rap is not without Bling)

then I have some that should fit the brembos (well they fit my old one cos I just tried)

pm me yer address

[Crap Tartan]

Hey Snap, yes I still have the original caliper on the rear!
The caliper has two pistons each with two seals (1 dust which is thin and the oil one which is much thicker) both pistons are the same size.

Will PM my address now..........

Yer a star!

[Crap Tartan]

Well thats the master cylinder ordered from Dennis Trollope Racing and looks like Snap has come to the rescue with the caliper seals!!

Dizz, hold fire on noising up that local Duke dealer please.

Just hope everything arrives in time and I can get it fitted and working in time for the WEEKEND!
(not easy as am away working for 3 days next week down in Surrey..................)

[dizzyblonde]

No worries CT

You can still ride with no back brake....dunno why they put one there anyway, I never use it

[Crap Tartan]

No worries CT

You can still ride with no back brake....dunno why they put one there anyway, I never use it

Wonder why that is then???

I do use it regularly but not a lot, it does make a diff when needing to slow quickly from speed and is very useful when needing to steady the bike for cornering when too much weight is on the front........................

[snapdragon]

post posted