2012 Superb 2, 140 cr. I only regularly do small weekly mileages (but then occasionally long distances) so once every week I brake hard a few times to clean things up. I have noticed that as the ABS seems to kick in the pedal travels much further....feels like it's gone soft. I can repeat it a few times. It stops very well, and brakes feel fine at all other times. Never had a problem stopping.

I had the brake fluid changed just before Xmas but it still behaves this way.

Is this normal? Should I be concerned?

Fats

 

No doubt the activation of the ABS will affect the feel of the brake pedal.

 

When scrubbing the brakes on my Superb I brake hard, but not hard enough to activate the ABS 

Thanks silver1011 for your response. No one else?

Maybe no one else ever tries to see just how quickly (or not) their car can stop? 

I am very easy on the brakes, try to anticipate traffic in front and behind to avoid heavy braking, but when I got this car I thought I would see how well it braked. I was extremely impressed.

On a clear, empty and dry road from about 60mph I pick a spot ahead (junction or tree whatever) and leave it as late as I think I can to brake and stop at that spot. Usually end up stopping 5-10 metres before. I now know what the car can do, and how stable it is when doing it.

ABS may go off, and that's when the pedal goes beyond usual travel.

Not that I do this all the time, happy to scrub off the brakes without that extreme, but from time to time....

Fats

That has always been my experience when deglazing the brakes with a very hard stop from high speed and usually downhill, if I dont do it often enough the brakes can glaze up enough that the ABS does not even kick in which just adds to the heat going into the pads and further glazing.

 

When the ABS cuts in normally on ice or a slipper surface the brakes are not being applied very hard and the heat is not an issue, that plliese ven to the way that many do an emergency stop, you are properly working your brakes to descale them as I do and I think what we are experiencing is localised fluid boiling or perhaps the friction material going spongy, I changed the fluid on my MK1 thinking it may have taken on moisture but it made no difference to the long pedal when brake testing.

 

I am glad you do it and wish others would as well, when I was younger there was no need, the brakes were used in anger all the time and frequently the ABS would cut in, now I drive for economy like you I do regular brake tests to deglaze the discs, I suspect that for many vehicles the ABS would not even cut in on a real high speed full braking effort emergency stop.

 

Editted, it could be that the fluid is recirculated back to the master cylinder each time the brake pressure is released, I think some aviation ABS systems work like that, I dont recall feeling it on previous vehicles though, usually Fords up till about 1990.

Edited 22 January, 20197 yr by J.R.

Thanks JR - very good explanation of what is probably causing the long pedal travel and good to know that someone else is experiencing the symptom in the same scenario.

Looks like nothing to worry about - I'll just keep doing the same on a regular basis to keep things clean.

I see you are in Picardie - we are down in the Charente Maritime. Got to keep a good look out behind over here when braking hard!

We have some British friends who have brought up 3 children here and all have learnt to drive and passed their tests in France. All 3 were taught to drive close to the vehicle in front so that when an opportunity to overtake arose they would not have to spend so long on the opposite side of the road...…. they were effectively taught to tailgate......

Fats

From my own experience of braking hard with the Superb, I'd guess that the softness you're experiencing under hard braking is the Brake Assist system kicking in. It uses the ABS pump to rapidly bring the brakes up to full application when it senses a rapid application of the pedal. This could leave the pedal feeling soft as you are now catching up with the system.

chimaera -  Ah...Brake Assist, that explanation seems to be exactly what is happening. 

Thanks