Spongy brake pedal - after new pads and disk

[Duncan_F]

Hi,

Recently purchased an RS4 which was in need of new brakes all round (factored in to the price) and I had put long pedal travel and spongy feel down to lack pad/disk material.
Just had new disks and pads put on, but despite the garage (audi Indy) bleeding the system about 4 times the long pedal travel and spongy feeling (little in the way of decernable bite point) are persisting.

Any thoughts as to what the issue could be?
Thanks

[JCviggen]

How are they bleeding it? I had a persistent soft pedal after a fluid change once, took ages to solve. Is it better when you (during braking) let off and go for a second application right away?

There's a particular method that needs to be used when bleeding, for a start it needs to go from right rear, left rear, right front to left front and don't forget that there are two bleed screws on each front caliper. Outer screws first IIRC.

Air can get trapped in the ABS pump if they really screwed it up, in which case it helps to have it activated during the bleeding via VCDS, or find a slippery surface and go nuts for a while...

[Duncan_F]

Thanks, that's helpful. Will test the second brake application feel.
They say they've vacuum bled it, but not sure the process above was followed, will check.
Want to rule out everything before have to start stripping/returning calipers.
Should the pad bedding in make a big difference to the brake feel, or is this more likely a bleeding issue?

[JCviggen]

Nah pads shouldn't make much difference at all.

I struggled on with a soft pedal for over a year (admittedly I was mostly abroad with no access to the car) and took several attempts to rectify. And nothing annoys me more than a spongy brake pedal!

[Duncan_F]

Tried the double pump of the break pedal, definitely a lot firmer on the second press like how it should be the whole time. Going to try bleeding the ABS pump to see it that sorts it.

[JCviggen]

That's how mine was, yeah. Bleed the pump and then the system in the order I wrote earlier, apparently it matters. I was somewhat skeptical but the first time we used the proper sequence it was solved.

[Covkiller]

This is an easy fix. Whilst your doing it you may want to change to braded hoses too.
You need to bleed the brakes properly as above moving from the furthest to closest in succession. Buy at least double what you need in brake fluid and completely flush the system twice.
Garages and peope says they bleed the system but they don't flush the system. I did this on mine and my brakes are rock solid.

[Damianos]

Hi, might also worth checking your master brake cylinder, especially if the issue disappears by pumping the pedal.

[Covkiller]

It's just air in the system 100%. For us old boys, Mk1 Mini's and Imps suffered from cronic air ingress. Pumping the brakes to compress the air was normal driving practice.