Monster rear brakes - help!!

[Count Steer]

But if you've ever done Alps (or Pyrenees) mountain riding, then you'll have more appreciation of the feeling that I kinda need the rear for the wet!!

Err...once or twice y'know. Seen a few hairpins and the bits where you think 'If this goes wrong on a bike, I'm over the barrier in freefall sans parachute' etc.

I didn't say you don't need one, I pondered on the apparent essentiallity of one for the wet. As I said, it's a topic for Survival Skills.

[A_morti]

The fundamental problem with the brake is that the master cylinder bore is too large compared to the piston diameter.

If the caliper is the root of the problem you may get away with a clean and reassemble, but if it's manky inside maybe put the seal kit money back in your pocket and buy a later caliper with larger piston instead.

[Noggin]

From memory, and experience, I'd replace/repair the master cylinder. I adjusted the pushrod fully up and it made bugger all difference to the lever pressure.
€15 gets you a Chinese mityvac from temu which allows you to bleed your own brakes

I just assumed that lack of use and a wide range of temperature up here has changed something in the brakes - or lack of use messed up the caliper!

I have a bleeding thing, but I think it still needs me to hold something or top up something whilst pushing the brake lever - which I can't do, don't have the reach . I'll have a look at the mityvac!!

But if you've ever done Alps (or Pyrenees) mountain riding, then you'll have more appreciation of the feeling that I kinda need the rear for the wet!!

Err...once or twice y'know. Seen a few hairpins and the bits where you think 'If this goes wrong on a bike, I'm over the barrier in freefall sans parachute' etc.

I didn't say you don't need one, I pondered on the apparent essentiallity of one for the wet. As I said, it's a topic for Survival Skills.

It's now 'essential' for the wet - but for me it's pretty essential for the wet going down the mountain!! The roads into some of the other resorts aren't full of hairpins! Where I live is (might have said this before ) 21 hairpins and 3 roundabouts down a mountain to get to the valley!! Hence my ideal is a rear brake! But, seemingly, chances are the standard one won't instil much more confidence than none!!

The fundamental problem with the brake is that the master cylinder bore is too large compared to the piston diameter.

If the caliper is the root of the problem you may get away with a clean and reassemble, but if it's manky inside maybe put the seal kit money back in your pocket and buy a later caliper with larger piston instead.

I might have a look for a caliper instead! It's looking like I'm going to try and go the VOSA equivalent route, so if that does happen, I can change the caliper and not worry about the Ducati dealer being a picky bastard!! (So need a fingers crossed symbol!! )

[Zimbo]

Pretty certain it'll be the master cylinder and that the caliper will be fine (I'm currently on my 12th air cooled Ducati, including three years racing the thinks).
I find the rear brake is fine for what I use it for - stabilising the bike on slow manoeuvres and a bit of extra braking when it's slippery. They don't generally lock up the rear wheel on a dry road but they should work.

[The Spin Doctor]

But if you've ever done Alps (or Pyrenees) mountain riding, then you'll have more appreciation of the feeling that I kinda need the rear for the wet!!

Err...once or twice y'know. Seen a few hairpins and the bits where you think 'If this goes wrong on a bike, I'm over the barrier in freefall sans parachute' etc.

I didn't say you don't need one, I pondered on the apparent essentiallity of one for the wet. As I said, it's a topic for Survival Skills.

I think it's called Staying Alive now

But thanks for the memories

[Noggin]

Pretty certain it'll be the master cylinder and that the caliper will be fine (I'm currently on my 12th air cooled Ducati, including three years racing the thinks).
I find the rear brake is fine for what I use it for - stabilising the bike on slow manoeuvres and a bit of extra braking when it's slippery. They don't generally lock up the rear wheel on a dry road but they should work.

I did think the caliper looked ok and I saw quite a lot of each piston whilst messing about and honestly don't think they are bad - but equally, I don't have much experience of these things!! LOL


I did find a new master cyclinder that appeared to be the same price as a second had one - then realised it was in GBP, not Euros , but I might still have a look for one online

[Noggin]

Oh, also met a couple of locals that ride, and didn't realise I do (cos I haven't really for so long!). So if I do get really stuck, I have people I can ask for help - maybe

[KungFooBob]

A lot of the Brembo stuff is rebuild/serviceable.

I rebuilt my Ducati clutch M/C. The kit had new seals, spring and piston for not a lot of money.

[Noggin]

A lot of the Brembo stuff is rebuild/serviceable.

I rebuilt my Ducati clutch M/C. The kit had new seals, spring and piston for not a lot of money.

Yes, but I'm not exactly a great spannerist - you can't probably do that without really thinking. I'm not convinced I could.

But I will spend some time researching a bit to see if I might be brave!!

[KungFooBob]

You just need a set of small circlip pliers

[Noggin]

You just need a set of small circlip pliers

Must remember to look in my tool box tomorrow - good chance I have some of those!! LOL

[Noggin]

I have measured the fixing bolts and that bit is right - but do these look the same?

The info is right and the fixing bolts are right, but I'm just checking with you more knowledgable types

[Zimbo]

Certainly looks the same ....

[Demannu]

Its a 40mm spacing with 6.5mm bolt holes.
Pretty standard.

[A_morti]

Yes. You want ps11 rather than ps13.

However you still haven't fully eliminated the caliper as the problem yet.

Rear brakes aren't a big system or hard to understand. A handful of bolts and you can take the whole lot off the bike to the bench and start pulling it apart.

Time to stop being scared and dig into it?

[Noggin]

Yes. You want ps11 rather than ps13.

However you still haven't fully eliminated the caliper as the problem yet.

Rear brakes aren't a big system or hard to understand. A handful of bolts and you can take the whole lot off the bike to the bench and start pulling it apart.

Time to stop being scared and dig into it?

Indeed. I have to go to Chambery on Tuesday, but after work on Weds, Thursday, Friday (one or all!!) I will have another look at it all and see if I can be sure what is what.

I just kinda wanted to find a reasonably priced part in case I need it and the one in the photo is actually quite a bit cheaper than any recon ones I've found (cheaper postage as well as lots seem to come from the UK! )

The description of the one in the photo is -

Brembo Rear Brake Master Cylinder PS 11 C Ø 11mm, color Black, fixing holes 40 mm, Top outlet, Ducati Monster Type

I've checked the info and it says it is the right type for my year of Monster, so it is at least an option if I can work out that this is the issue!!

Been told to look for a 12mm as it would be better for the 'two' pistons (caliper is not a single piston one), so will have a look for that too in case I can find one with the same fixing hole distance.

Extra wary really as now I've had a bit of transport, I do not want to fuck it up and not be able to use it at all! But since I'm riding without a rear brake (and so won't ride down in the rain) I guess it can only be a positive or samesame result!! Hopefully

[A_morti]

The smaller the master cylinder, the more lever movement you'll need, but the more hydraulic advantage you get. I'm assuming yours is 11mm now and you want more power, so I'd skip 12&13, stay with 11.