question for tame technican - brakes

[scooters]

Hi, I have a 2006 140 tdi golf and when under heavy braking it is possible to touch the floor with the pedal. Is this right? Fwiw the car seems to be stopping ok. Any advise appreciated

[T89 Callan]

You shouldn't be able to hit the floor with the pedal.

Air in the system? Fluid been boiled at some point?

[heebeegeetee]

scooters said:

and when under heavy braking it is possible to touch the floor with the pedal.

Er, no!

Sounds like there is air in the system. Do you/have you ever need to top up the brake fluid?

The pedal should be nice and firm under foot, and shouldn't get anywhere near the carpet.

Try switching off the ignition, then pump the brake pedal a few times. This will exhaust the brake servo, and you should feel the pedal go really hard. Then, if you start the engine with the brake pedal pressed, you will feel the pedal go down slightly, and feel softer. This is the assistance that the brake servo offers.

But the pedal feel should remain consistent.

Have you had any work done to the brakes? Has the brake fluid ever been changed? (It should be changed every two years, ideally).

• Edited for spellinge.

Edited by heebeegeetee on Tuesday 13th April 20:29

[cpas]

Possibly under extreme braking the brake assist will cut in, and this makes the pedal go a lot further down, but not under normal circumstances!

[BoraBora]

a friend had this problem on his rover, turned out to be an internal leak on his ABS pump, but thats probably one of the last things you should be checking, as above, change the brake fluid, bleed the brakes, check your brake hoses arent balooning (unlikely)

[Tame Technician]

The modern Audi/VW brake servos are very over assisted, so if you sit in the car stationary, at idle and press the pedal it will creep pretty much all the way to the floor. You ask anyone with the slightest mechanical knoledge is the right and the anser is NOOO!, BUT they all do that, even brand new ones, its just how Audi brakes are, the proof that this is actually ok comes when driving the car.

When driving down the road you should never be able to get the same ammount of pedal movement, because the car will brake very heavily with very light pedal pressure, so what felt like normal brake pedal pressure when you were staionary would actually have the ABS on and you half way out the screen.

So when driving no the pedal should never hit the floor or even get near it. But it is normal for an A3/Golf pedal to creep down towards the floor when the car is stoped and the engine running.

Its either the brakes them selves are masivly ineffecient (worn discs + pads, partially siezed calipers) so you are having to use so much pedal pressure you are getting the audi creeping pedal thing even on the move, or there is air somwhere in the system.

Does the pedal get better if you pump it a few times.

Edited by Tame Technician on Saturday 17th April 23:21