Rear brake problem

[Bulloween]

Hi guys, I'm having problem with my rear brake. My rear brake stops biting the pad. I have to push the rear brake lever once (like pushing air) then on second push it reacts but don't bite the pad. So I remove al the pads, rotors. Changed the pads, new brake oil, clean the brake pistons and change whole 15 seals (dost and oil seals). I install the pads bleed the air. But it's still like pushing the air. I forget to check the brake disk thickness. An the result is shocking. It's thickness is like 3.2 mm. Way lower than the limit. So I ordered new disk. But do you think it is the whole reason of my problem?. I don't want to cry after changing brake disk. (by the way front disks thcknesses are like 4.2)

[SB]

You haven't mentioned which model Vara you have !

Bleeding the brakes is complicated the complete system (front and rear) has to be bled in a set sequence.

Do you have access to a manual for your Vara ?

[Skye]

Agree with SB, it isn't bleeded correctly and in the front wheels left side you have the piston to pump up a pressure for the middle piston in the caliper.

Also check the hose from the back reservoir. It can be broken inside and air might come in. You will notice this if the rubber in the lid of the brake fluid reservoir had been sucked out into the reservoir.

[Bulloween]

I have a 2004 abs version. I put the fluid with a vacuum machine and bleed it two times. I have this bike and my other bike (cbr 1100, the same brake system and parts) more than 10 years. And I did the brake job more than 10 times. , so I don't think its an air problem. My main concern is the thickness of the disk. Can a very thin disk causes a problem like that?

[Skye]

No..

Better in that way do a refurb on the caliper. Change rubber covers and sealings, as the mechanism may stuck

https://www.davidsilverspares.co.uk/XL1000V4-VARADERO-2004/part_100863/

[Bulloween]

I changed everything about break system 

[Skye]

Had a problem once with rear brake. It was the hose from container that had crack from inside

[Bulloween]

So I'm going to check the whole hoses.

[Skye]

Since it is rear brake, the hose is about 30 cm long. You can easily change it

[Bønne]

The tube from the reservoir has no influence on the pressure, as it only feeds the master cylinder with brake fluid... unless the tube and reservoir has run completely empty, then the master cylinder will suck air instead of fluid.

To me it sounds like air in the system when you can pump it and the pads won´t bite. Are you aware that when bleeding the rear brake you have to bleed the front calipers too?

Because of the DCBS system, the rear brake also activates the middle piston in the front calipers, so these has to be bleeded too.

Start with the left front caliper; lower bleed valve, rear brake pedal.

Then the right front caliper; lower bleed valve, rear brake pedal.

Rear caliper; front bleed valve, rear brake pedal.

Rear caliper; rear bleed valve, rear brake pedal.

[Bulloween]

Hi guys, thanx for your repplies. I found the problem. My secondary master cylinder on the left front wheel seems like bleeding fluid. The seals in the cylinder were deformed. I'm going tho replace them. And hope this will the end of my rear brake problem 

[Skye]

Good, that you found the leakage.