Bleeding useless 1200R rear brake

[SteveG]

Literally... anyone know how to stop the rear brake constantly needing bleeding? Freshly serviced or bled - fine. Within month or so useless. No apparent leaks or fluid loss.. any ideas?

[rollo22]

Silly question you are using new fluid cos its hygroscopic and any moisture will not help the performance of the brake.
Could have a chat with the dealer it was purchased from for a complete brake service.

[Darkness]

Our own Pedro has had problems with his.

He has chronicled it in t’other place:

https://www.ducatiforum.co.uk/thread...ylinder.69637/

A new master cylinder with new high temperature fluid appears to have fixed his.

Girlfriend has the same problem with her Monster 821. She bought it new two years ago and the back brake lasts about a month to six weeks before it needs bleeding again.
The bike went back to Moto Rapido many times under warranty, but despite new master cylinder and new brake caliper they have not fixed it.
My wifes two year old Monster 821 has had no problem at all with the rear brake, nor has my 939 Supersport with the same rear brake components and system.

[Dukedesmo]

Maybe it's the 916 'curse'? - bike is renowned for;

A. having a crap rear brake
B. needing to be bled on a constant basis.

I always thought it to do with heat transfer from exhaust to master cylinder but who knows?

Plus ca change eh?...

Originally Posted by Dukedesmo

I always thought it to do with heat transfer from exhaust to master cylinder but who knows?

Plus ca change eh?...

Doubt if it is heat related. None of our bikes has a cat anymore, but when the Supersport did, it was much nearer the rear brake system than the Monster was, bit the SS has had no problems.

[mickj]

Keep reading about the crap rear brake on Ducati's but my two year old M1200s has a brilliant rear brake still as strong as the day I bought the bike. Seems to be a bit hit and miss.

[damien666]

Not sure if PTFE tape is compatible with brake fluid. You could put some around bleed nipple thread temporarily to eliminate air being drawn in from there?

[Pedro]

As the thread mentions I’ve changed the master cylinder recently - pulled the old one apart and it does show some wear down one side of the bore caused I think by less then a straight push by the pedal link rod. That being said I don’t use the rear brake much so I’m more suspecting the master is faulty, either elipitical or has a defective seal that is allowing air to be drawn in. There’s never been a sign of leaking and Rapido checked the abs pump, all good.

What did help was one of these
http://www.stahlbus.com/products/en/...stem/index.php
Makes filling and bleeding a breeze, still needs the calliper off and inverted. Very easy to get an air free flow and no air gets drawn in

6 weeks on pedal remains good, wheel can be locked/abs triggered

After all that I’m pretty sure the master was faulty from new, there’s been a lot of reports of Multistradas and Pani’s with the same all built around the time, maybe a duff batch. Steve, as yours is the same age as mine it might be the same

[Pedro]

Originally Posted by BobT

Girlfriend has the same problem with her Monster 821. She bought it new two years ago and the back brake lasts about a month to six weeks before it needs bleeding again.
The bike went back to Moto Rapido many times under warranty, but despite new master cylinder and new brake caliper they have not fixed it.
My wifes two year old Monster 821 has had no problem at all with the rear brake, nor has my 939 Supersport with the same rear brake components and system.

Girlfriend and wife? Lucky or brave...

I’d be having a look at the lines, there are reports of models being recalled due to defective termination of the hose and fittings. After that it’s either the abs pump or defective installation which is highly unlikely at MR

[SteveG]

Cheers guys. Ped.. your answer makes most sense. I’ll give you a call sometime to catch up.

[Pedro]

Originally Posted by SteveG

Cheers guys. Ped.. your answer makes most sense. I’ll give you a call sometime to catch up.

Cool, be good to chat

[Saint aka ML]

Is that valve for calliper or master? Mine dies 3 weeks after bleed. 1st problem is valve in exhaust prevents full lever movement, especially with spark exhaust. So getting it cut out this month.

But that valve looks to make bleeding easy.

[Pedro]

Originally Posted by Saint aka ML

Is that valve for calliper or master? Mine dies 3 weeks after bleed. 1st problem is valve in exhaust prevents full lever movement, especially with spark exhaust. So getting it cut out this month.

But that valve looks to make bleeding easy.

Calliper.

My pedal will hit the exhaust valve but only when it needs bleeding - normal travel is about 20mm. I have an Arrow can and fitted a spring underneath as the can pushed the exhaust out , the spring pulls it back