No brakes on one side(Right!)

Hi everybody! After the pain to remove and to repair the steering box on my Disco 2, I decided to wash the old oil traces from the engine compartment.
Going to a test drive on the hills, I tried and used a lot the HDC to keep the system working.
After 2-3 miles I arrived home with the right front wheel blocked, smoke was coming out like in the good days.
I took the right front wheel out,the disc was rock solid. I release the bleeding screw, and the fluid was going out with some pressure.Wheel was rotating free, disc is blue...

Today,trying to refit everything together, was surprised to see that there is not fluid coming out as the brake was pressed. Very hard, after braking with the engine started, it was ****ing a little.
Hawkeye fitted, no ABS fault codes,everything seems right. Braking from the Hawkeye, right front and rear, no action. Left, was strong and stopped the car on each wheel pressing.

Any idea? Bloody ABS module? The pedal is flat as a flat tire,while the car is moving and braking, it goes to the left a little as the right wheels are not stopped.

sounds like abs valve block or shuttle valve fault

OK,but no fault codes or three amigos! I seen on RAVE something about self-protection of brake circuit against overheating,but how to unlock it?:doh:
"Brake overheat prevention
To prevent the brakes overheating, the SLABS ECU monitors the amount of active braking employed and, from this,
estimates brake temperature. If the SLABS ECU estimates the brake temperature has exceeded a preset limit, it
flashes the HDC fault warning lamp and sounds the audible warning continuously, to indicate that HDC should be
deselected to allow the brakes to cool. If active braking continues and the SLABS ECU estimates that brake
temperature has increased to an unacceptable level, fade out is employed and HDC is disabled. After fade out, the
audible warning is discontinued but the HDC fault warning lamp continues to flash, while HDC is selected, until the
SLABS ECU estimates brake temperature to be at an acceptable level. This calculation continues even if the ignition
is turned off, so turning the ignition off and back on will not reduce the disabled time. When the SLABS ECU estimates
the brake temperature to be acceptable, it extinguishes the HDC fault warning lamp and illuminates the HDC
information warning lamp to indicate that HDC is re-enabled. The disabled time is dependent on vehicle speed; typical
times at constant vehicle speeds are as follows:......"

check the simple stuff first . brake hose may be blocked or a line kinked somewhere

Some news after today work:
-it's right-front and left-rear that are not working at all.
-trying to bleed them,no fluid is coming out from the bleed screw under braking(it was no problem to the rear left wheel,but no fluid is coming there).
-taking the pipe out of the modulator, braking, no fluid out of modulator, just a spoon,but no high pressure.
-cleaning the caliper,the one with the blocked wheel, no problems,the original seals were better then the Britpart , so kept them.
-the pipe have no problems.

Going for a drive-test,the same problem,the bloody wheels don't want to brake, as there is no fluid coming under pressure to the calipers.

The HDC works on the 2 working wheels, stopping the car when pressing the button and in Low.

Next move? Shuttle valve cleaning and inspection? Some electric impulse is saying "don't send fluid to these 2 wheels"! How can this be repaired?:doh:

its not repaired its replaced doesnt always rectify the fault and you will end up replacing the valve block as i have said before....
you will need to carry out a modulator bleed one replaced using suitable diagnostics.

the above two reasons are the only reason for the symptoms you are getting.

i may be a relativly new member on here but i have been a specialist in land rover repairs and diagnostics for many many years so if you dont want to listen to me about your fault thats fine!!.... but i bet you will end up doin what i said eventualy and finding your fault.

A little update:
-ABS module dismantled in pieces, cleaned,air pressure blown, and reassembled. Shuttle valve switches checked with the Ohm meter, correct values were shown when both open, both closed, one closed. No fluid on the switches.
-pipe out of the master cylinder, blowing pressure air, surprise... the caliper did it's job, wheel is rock solid, tried it 10 times to be sure.

Master cylinder is on it's way , will fit it soon.

Each diagonally placed pair of wheels are braked by a circuit of the master cylinder: front right-rear left is the front part of the cylinder, front left- rear right is the rear part of it.

Anybody know a modulator bleeding procedure using Hawkeye?

flay said:

A little update:
-ABS module dismantled in pieces, cleaned,air pressure blown, and reassembled. Shuttle valve switches checked with the Ohm meter, correct values were shown when both open, both closed, one closed. No fluid on the switches.
-pipe out of the master cylinder, blowing pressure air, surprise... the caliper did it's job, wheel is rock solid, tried it 10 times to be sure.

Master cylinder is on it's way , will fit it soon.

Each diagonally placed pair of wheels are braked by a circuit of the master cylinder: front right-rear left is the front part of the cylinder, front left- rear right is the rear part of it.

Anybody know a modulator bleeding procedure using Hawkeye?

Click to expand...

Are you saying you fixed it?

CharlesY said:

Are you saying you fixed it?

Click to expand...

Not yet(my brake cylinder is traveling now...), but as long as it works with air, at 2-3 bar(normal tyre pressure) it probably will work with a new master cylinder using liquid instead and having a higher pressure.
Will find it by the end of the week.

Hi guys! Just a last update on my brakes problem!

I received yesterday the new master cylinder, fitted it today.
The brakes are now working perfect.

Conclusion:
-if two diagonally placed wheels are not working,it is because one of your brake circuit didn't work
-if using a tester,one of your shuttle valve switches don't work or the test failed,it's because the brake fluid is not pumped in half of your modulator,because of a bad master cylinder.

I was tempted to change the shuttle valve switches,very common failure on our Discoverys, finding also a new SLABS module or repair center for ABS modulator,but the repair was very simple: new master cylinder!
It's probably because one of the valves inside the cylinder is blocked or worn o-ring. Forensic work in the near future to see what's inside.