Brake Pedal Problem

[Chard1966]

The problem is on a 1996 Sharan TDI

 

When using the brakes for long periods

ie; not on off braking, the pedal travels almost to the floor (very scary)

 

If you lift off the brakes and re-apply them they are then back to normal

as sharp as a Knife

 

There are no leaks or loss of Brake fluid

.

I have had a lot of experience with Galaxy's Alhambra Sharan's

we have 5 in our family.

 

I know the mk1 pedal goes down half way when applying pressure when on tick over

spoke at length with a ford technician he assured me this was correct.

 

Does any one Know if there is a pressure release valve for the brake Pedal? Servo

or has any one had this problem and had the fault diagnosed or fixed

[chrispb123456]

Hi there

Sounds very much like master cylinder

[chromedome]

Could be a seizing caliper. Given time the piston could fully retract so your brakes seem ok. With continous braking the piston may not retract quickly enough thus allowing excess pedal movement.

 

Have you also checked that the pads are not jamming in the calipers allowing free movement of the piston before taking load.

 

As previously mentioned, could be master cylinder, the seals have been know to "flip" if the brake fluid is pushed back into the system during brake disc replacement. Excess fluid should be let out of the bleed nipple to prevent this and to protect the ABS system.

[Chard1966]

The problem is not to do with the brakes heating up ,

it happens when you keep your foot on the brakes ie

slowing down on hills, slowing down slowly

braking from any speed where you have to keep constant pressure on the pedal and it drops to the floor .

They work fine for on off braking

[sasquartch]

The problem is not to do with the brakes heating up ,

it happens when you keep your foot on the brakes ie

slowing down on hills, slowing down slowly

braking from any speed where you have to keep constant pressure on the pedal and it drops to the floor .

They work fine for on off braking

 

Sounds like air in the system assuming you have no leaks.

 

Would suggest you bleed the system after thoroughly checking for leaks at each wheel and master cylinder. That's pretty easy and cheap and may be the solution. If that doesn't help it sounds like the master cylinder.

[Richard gal]

Its the seal in the master cylinder, the fluid is getting past it... slowly.

[Chard1966]

I have now changed thew Brake master cylinder (genuine part from VW