disco 1 300 tdi faulty brakes ( help needed)

hi, i have a disco 1 that is having problems braking!
some times its fine and feels good on the pedals then sometimes the brake pedal just locks and wont go down, the pedal is not getting stuck it has a small amount of travel and then goes very hard.

can anyone help me with advise as to what might cause this, iv taken it to a garage who said i need new discs and pads but i cant see this being the problem.

any help welcome

hilts said:

hi, i have a disco 1 that is having problems braking!
some times its fine and feels good on the pedals then sometimes the brake pedal just locks and wont go down, the pedal is not getting stuck it has a small amount of travel and then goes very hard.

can anyone help me with advise as to what might cause this, iv taken it to a garage who said i need new discs and pads but i cant see this being the problem.

any help welcome

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I wonder if the vacuum pump is playing up. You say there is nothing sticking the pedal but that the pedal is solid. With the engine off discharge all the vacuum by pumping the pedal several times and see if thats the symptom you have when its exhausted. Could be you are driving along, a few presses of the pedal takes all the vacuum away and hey presto no brakes.

Once you have done that see how long it takes to build the vac back up again to a normal pedal and count how many presses it takes to go solid again both with the engine running and off.

Dont see pads or discs giving that fault to be honest, but you can see the condition through the wheel anyway, and the garage should have done a brake test. They either work or dont.

i had a feeling it might be the vacumn pump but was not sure how to test it, will try this later when back in workshop and let you no the reults,
many thanks for your help

have you serviced the brake pistons, they may be catching might be worth giving them a rub down with pads out....

wouldnt have thought the pistons would 'catch' more likley thr pistons would seize and or leak not give a hard pedal. Vacum pump could well be on its way out. Question: how long say on tick over should it take to build up the required vacum? Its a question ive always asked and should there be a one way valve in the servo? Im guessing so but still not checked mine lol

jai_landrover said:

wouldnt have thought the pistons would 'catch' more likley thr pistons would seize and or leak not give a hard pedal. Vacum pump could well be on its way out. Question: how long say on tick over should it take to build up the required vacum? Its a question ive always asked and should there be a one way valve in the servo? Im guessing so but still not checked mine lol

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With the brakes exhausted keeping your foot on the hard brake pedal, start the engine and it almost instantly starts to fall to the floor. If you are having to rev the engine up to get vacuum then I guess its fooked. Tested trillions in the mot test and yet to find one that takes any time to build up vac.