Hiya guys, Am having probs with a lack of brakes on my 2001 vrs

As on start up, the pedal is practically on the floor before any bite and the ABS cuts in whilst stopping.

You can pump to improve, but then goes back to the floor.

When you do brake, you can feel the brakes working very slightly whilst the pedal is on the way down, but no real brakes until very near the floor.

There was a vacuum hose under the inlets which my mechanic advised to change as it collapses and could cause braking problems.

I have changed this, whilst changing, I could hear air leaking out so there is possibly more air in the system. The air in no longer leaking, but still no improvement in braking.

Fluid is all good, so there are no fluid leaks.

Any help greatly appreciated by ourselves

David & Martin

It sounds like your brakes need bleeding properly, including the ABS block. In order to do this, you need VCDS or a dealership computer.

Thanks for the response.

Will have to do that thoroughly.

Out of interest, do you know why you need to have the VCDS to to it?

And is there a specific order to bleed properly (or just the usual, furthest from cylinder to nearest?)

Thanks again,

David & Martin

AIUI, standard bleeding risks:-

1) Over-running the master cylinder and reversing the seals (actually, this may have happened already. Keep in mind I'm working with a net description and only know what you've told me about the history of the specific car).

2) Getting air into the ABS block, where it gets trapped.

VCDS cycles the brakes for you whilst you're doing the bleed, and will prompt you on which wheel cylinder to work on next. It also bleeds the ABS block, which a conventional manual bleed just plain doesn't.

Thanks for that.

I didn't realise the VCDS was so clever!

David & Martin

Right, a quick update....

Bleeding the brakes today has seen no improvement.

What has got us completley puzzled is that....

When the engine is Off and you pump the brake pedal, the brakes are at the top as they should be and do not sink to the floor.

As soon as you turn the engine On, the brake pedal sinks to the floor.

Any ideas what this is, and what could be causing it?

Help greatly appreciated (as always)

David & Martin

The pedal will sink a little when you start the car due to vacuum building up in the servo.

Shouldn't go all the way to the floor though, unless the MC is giving up with the extra pressure.

What are the other symptoms of the MC packing up?

All the calipers have been bled so there is no air in the system, the only problem I found was on the passenger rear caliper where the copper washer and the metal washer were put on the wrong way round. This has now been corrected (very very slight leak, not enough to cause the problem we have)but still the same. Pressure when off, no pressure when on.

I really hope it isn't the MC as we have only had the car a fortnight, and have already shelled out £500 on a top end rebuild!

David & Martin

Have you bled the master cylinder? There should be 2 bleed nipples on the MC itself, one on the front and one on the side I think. Had a similar problem once, spent a day messing around with them until I found them. Both will probably need doing before you feel any improvement

Not as of yet, no.

Will have to give that a try tomorrow and update with results.

Also, (Daft Qusetion, I know) do you need the engine running to bleed MC, or is it best to do it with the engine off?

Thanks for the info

David & Martin

Edited 15 April, 201115 yr by David_Martin

Sounds like a daft question but all pads are clean and free to move in carriers, if pads are seized it can cause crap pedal aswell

Yep all the pads are clean and free, Am gotta try and bleed the MC in the morning though! Just hope it works but would i need to bleed brakes again once i have done the MC? Again thank you to all you guys that have replyed and keep the ideas/Suggestions coming!!

David & Martin

We had the brake fluid changed about 2 years ago.

All the fluid was drained and then new added big mistake! peddle went to the floor no matter how much we bled the system. I think it was mentioned on here to drive on some grass and make abs work hard thus trying to get the air out of the abs unit. I didn’t try this I took the car to vw and they hooked it up to the computer to bleed the abs unit.

This worked wonders, dam scary not having brakes. Had a couple of scary moments on the drive to vw.

Thanks everyone for your help.

Bled the Master Cylinder, there was air in the front bleeding nipple. Problem Solved!! *punches air*

So that was 4 hours wasted yesterday making sure that there was no air in the brakes, but at least I know there is no air in the system now.

What a result, over the moon.

David & Martin