cooked brakes

[airedale]

Discovery 2 year 2000 td5 with abs sls etc. After a sequence of very heavy braking, brakes red hot and allmost gone all together, I then lost a firm pedal and whilst it will still stop the car. the pedal under pressure goes slowly to floor .There are no leaks. Replaced master cylinder, no change. replaced flexi pipes for goodrich ,no change. brakes been bled using two man method and pressure bleeder, no change.There are no abs lights on (and the bulbs are working) Any Ideas greatly appreciated.

[lookskyward1]

Firstly, you should'nt need to brake that hard and often that you cook the brakes.:eek:

There is no doubt that the fluid that was in the car picked up a lot of air when you cooked the brakes. The whole system needs to be bled, changing the fluid completely. Use the pressure bleeder to flush the fluid right through, don't bother with someone pushing the brake pedal. Start bleeding at the rear nearside, rear offside, front nearside and finally the front offside brakes. You will need a lot of brake fluid to ensure you get all of the air out.

Good luck, it may be time to enrole for an advanced driving course while you are at it.:rolleyes:

[Satancom]

Yeah you will have boiled the brake fluid and killed it. As lookskward says, change the fluid completely! Also is it an auto? If not try changing down gears to use engine braking as well as the brakes to slow down!

[airedale]

The System has had at least a gallon of fresh fluid through it, completely replaceing the old fluid with new.this has made no difference.

[TEMPL4R]

Have you tried bleeding with the ignition on or engine running?

The ABS pump should bleed the system properly.

Chris

[airedale]

Yes its been bled engine running and not running.and with a combination of the two.

[DeanV8]

Yes its been bled engine running and not running.and with a combination of the two.

That being the case, it sounds like you've glazed the brake pads, from getting them way too hot.

Taking them out and filing a few thou of the surface would sort it out, in all probability, but it's just not worth it.

The heat cycling will have affected the material, so just bin 'em and fit some new ones.

Had to do this with my DII, and change the discs because they had heat annealed as well, and warped, despite only being 30 thou down off full thickness.

It is worth remembering, though, that bleeding the brakes should be done in the order that the manual, or Rave CD, says - or it won't be as effective. Found that out the hard way.....

Cheers

Dean

[airedale]

As the brakes have been apart I have allready fitted new discs and pads.I have also bled them in the order reccomended in the manual.

[DeanV8]

As the brakes have been apart I have allready fitted new discs and pads.I have also bled them in the order reccomended in the manual.
BLIMEY!:(

Only thing I can think of then - when you say there are no leaks, do you just mean fluid leaks? Perhaps you have a vacuum leak associated with the servo (sorry if you've already been there....).

Could be the pipework, or the servo diaphragm itself, has a perforation somewhere?

That said - I've just been out and tried mine and, whilst it works perfectly fine, if I sit there with the car stationary with my foot on the pedal it will slowly go to the floor. This is just the servo assistance dying off when the vacuum is being defeated in the servo by prolonged pressure on the pedal, and is normal. My two RRC's and my brother-in-law's DI all did it, too. Is that what you're describing?

Cheers

Dean

[airedale]

Hi Dean
I did mean just fluid leaks and I am really glad you posted as you have probably just stopped me going insane and heading for the nearest bell tower overlooking the LR factory with a high powered rifle!!! You have just confirmed my own thinking ,that this is a servo fault,the pedal does as you describe when stationary but also does it when in normal driving,The question now is ..... Is it the servo? seals? the pipe work? pump? diaphragm????????????????????????????????????????? ??????? AAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAA
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[Underdog]

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.....................*&^^%$&&^()(&^**&^&^%%$£££%"$&%&*^(*))-90


Hee Hee, welcome to the joys of Land Rover ownership!!:D