Spongy brake pedal

[Boldy]

I have a MK6 R and replaced the front rotors and pads over the weekend, DBA T3 rotors and silly me I went with Bendix Euro+ pads.

After install the brakes were making a strange noise and the pedal felt very soft - unlike before the change. Turns out the new pads didn't quite fit and when the caliper engaged it sort of cocked the pads so only half would engage the rotor. After enlarging the lugs on the pads they fit perfect and noise gone however crappy pedal remains (I don't like it), though braking performance seems good.

I've re-bleed the front brakes with no air detected and the pedal still feels soft. Thinking back, I had a mate over who was giving a hand and I recall that he started to push the brake piston back in without removing the reservoir cap - he seems to think it was only a couple of turns of the tool. Could this have damaged the master cylinder and potentially that's the reason for the soft pedal, or would I have other/different symptoms?

Any suggestions?

Thanks!

[brad]

They probably haven't bedded in properly yet. I know the Bendix are supposed to have "super-lazy bedding in technology" and a whole heap of other marketing BS but you may have to do it the old fashioned way.

BASIC INITIAL BRAKE BED-IN - STREET - Disc Brakes Australia

I agree. Bendix = ppphhhttt!

[nat225]

abs pump bleed done?

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[Boldy]

abs pump bleed done?

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No, should I need to?

[nat225]

No, should I need to?

yes

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[Boldy]

As I'm unsure of the process to perform the abs pump bleed I googled it - found this on the ross-tech site.

"This procedure details how to bleed the ABS pump when replacing brake fluid. This procedure is NOT necessary unless your ABS pump has gone completely dry. For normal brake work including fluid replacement, hose replacement, pad replacement, etc. this procedure is NOT necessary. Also, this procedure does not take the place of good ol' fashioned brake bleeding with one person operating the pedal while the other person opens the bleeder valves one by one and collects the discharged fluid."

So are you saying that the abs pump went dry?

[minke]

Two questions I would be asking myself. Did you bleed in the correct order? My understanding it is as follows
Pax front
Driver read
Driver front
pax rear

Also if you're worried about broken master cylinder - feel behind the brake pedal - it can sometimes leak down there.

Could you have damaged the seals when pushing back the pistons? Were all the dust boots in good working order? Were the pistons pushed back squarely?

Just some random thoughts.

[Boldy]

Thanks nat225 and minke for the suggestions.

I only bled the front and only as a precaution, as I didn't expose any air to the system - no air bubbles came out when I did bleed.

No leaking brake fluid in behind the pedal, nor anywhere else (reservoir/cylinder/calipers/ground).

I've re-inspected the seals - all seem ok, I used a piston pusher inner-er tool to reset the pistons.

Obviously it's something and I'm yet to find the answer, so all suggestions are welcomed and appreciated.

I did notice that a slight sound has returned when pushing the pedal down with the ignition off, sort of sounds like a stretched spring - thinking it might be the pads still not sitting correctly as it's very similar to before. Perhaps the pads need to bed in a little more?

[brad]

According to the VW workshop manual the bleed sequence is:
front left
front right
rear left
rear right

If you didn't break into the hydraulics there shouldn't be air in the system - I still think you need to bed the pads in properly (you haven't mentioned if you've tried that or how many kilometres you've driven since fitting).

If you had to file the pads to make them fit I would be ringing Bendix and discussing their lack of quality control and a set of pads that fit without having to modify them.

I assume you torque the bolts? Especially the slider pins?

[Boldy]

After speaking to a local brake and wheel shop they seem to believe that Bendix doesn't make a pad to fit the Golf R and subsequently believe the pads I have are actually for a GTI. I going to change them over to Remsa pads and see how I go.

To make matters worse, Burson Auto (store I brought the parts) recommended these pads, subsequently they want to charge me a $25 re-stocking fee to get a refund. To me it's a clear case they stuffed up and supplied the incorrect part, at no point did I request a specific part number for the pads, I relied on there expertise and recommendation. It's not so much the $60 for the pads but the stuff around it has caused which gets my goat.