Rear Brake Useless

While tightening the rear wheel nut and holding down the rear brake pedal, I find the rear brake on my 1199 is useless.
If I pump it a few times, it holds, but not enough to keep the wheel from turning while tightening the wheel nut, and barely slows me down while riding.
This is a dedicated track bike; never use the rear brake, unless I'm remounting the rear wheel.
But I figure it may be a good idea if I have an unplanned trek into the grass to have it work.

I replaced/bled the rear brake fluid--no change.
I didn't remove the rear caliper while bleeding the system that I see is recommended by some.

The attached picture shows how far the plunger goes into the master, basically compressing the return spring.

Does this most likely look a problem with the master?

I found a Master rebuild kit on MotoWheels; it gives a half dozen master model numbers that it is compatible with. I don't see anything close to those on my master.
Anybody know if the rebuild kits are universal?

Other option is to buy one new, or used on eBay.

Anything I should be aware of before I remove the master to prevent issues when I replace it.
I can tell that I'll have to do something to keep air from getting into the brake line leading to the ABS pump.

Thoughts/recommendations?

Have you bled them? Leaks?

Bled the brakes, no visible leaks.
Didn't see any bubbles come out while bleeding from the caliper.

I should’ve specified vacuum bled. Sorry. I wonder if some air got trapped either in the ABS block or behind the piston

No to the vacuum bleed. I suppose I could get/borrow a vacuum bleeder to see if that helps.

Do that first, the handheld ones are as cheap as and all you need, otherwise a rebuild might take you an hour at most from start to finish

Take the caliper off, turn it over, stuff an appropriate something between the pads, make sure its still below the master, apply brake, tie it off (the brake lever so pressure is retained). Leave overnight then reassemble. The constant pressure forces the air bubbles up into the master since the pressure is applied the port is open. Just the same as tying off the front with more ass pain to achieve.

Take the caliper off and elevate it higher than master when bleeding.

From the service manual:

Ducati bike in shocking "rear brake is useless" thread..... say it isn't so

Same issue on my 1299 buddy,.,,, when i do tire changes i also need to remove the rear caliper and bleed them...you must remove the caliper, turn it over, elevate it then bleed at the caliper. I'm able to do this without the VAC...

good luck

JAG

is that common in the US to work with vacuum?
in Europe, EVERY professional tool pushes brake fluid with pressure from the top in.

chris16 said:

is that common in the US to work with vacuum?
in Europe, EVERY professional tool pushes brake fluid with pressure from the top in.

Click to expand...

thats how i do it too....

chris16 said:

is that common in the US to work with vacuum?
in Europe, EVERY professional tool pushes brake fluid with pressure from the top in.

Click to expand...

I usually go with the standard lever action but if you run into a stubborn situation then resort to vacuum. Sometimes it helps.

bp_SFV4 said:

Take the caliper off and elevate it higher than master when bleeding.

From the service manual:

View attachment 51838

Click to expand...

I do not have problem with the rear brakes doing it just as I described. Not with the caliper above the master. Same as when you tie off the front. Constant pressure forces the bubbles into the reservoir.

jmlrkvmd said:

While tightening the rear wheel nut and holding down the rear brake pedal, I find the rear brake on my 1199 is useless.
If I pump it a few times, it holds, but not enough to keep the wheel from turning while tightening the wheel nut, and barely slows me down while riding.
This is a dedicated track bike; never use the rear brake, unless I'm remounting the rear wheel.
But I figure it may be a good idea if I have an unplanned trek into the grass to have it work.

I replaced/bled the rear brake fluid--no change.
I didn't remove the rear caliper while bleeding the system that I see is recommended by some.

The attached picture shows how far the plunger goes into the master, basically compressing the return spring.

Does this most likely look a problem with the master?

I found a Master rebuild kit on MotoWheels; it gives a half dozen master model numbers that it is compatible with. I don't see anything close to those on my master.
Anybody know if the rebuild kits are universal?

Other option is to buy one new, or used on eBay.

Anything I should be aware of before I remove the master to prevent issues when I replace it.
I can tell that I'll have to do something to keep air from getting into the brake line leading to the ABS pump.

Thoughts/recommendations?





View attachment 51837

Click to expand...

On further review, are you sure you’re getting the full rear brake lever travel? The spring looks fully compressed. On my V4, I have no problems locking the rear brake and I’m not sure they’ve changed the rear brake for decades

where is this bracket ?

if bled properly, the brake will hold the rim. We had the nut over torqued by a track vendor, and had a 6' cheater pipe on a breaker bar with 3 mechanics pulling on it, until the braker bar head snapped on two different breaker bars. and only foot pressure on peddle to hold rim, in 1rst gear. I was standing on it with as much pressure as i could apply.

This is on a 10 year old 1199s so like stated, bleed by raising caliper bleed nut to the highest point with caliper pistons pushed in, and use a spacer if need be to keep pistons locked in.