ABS PUMP CRAZY NOISE??!

P

Penelope

Member
 London
[vimeo]https://vimeo.com/434084888/b75f350abb[/vimeo]


The ABS/DSC 5Df0 5Df1 issue is well known and so are the solutions ie Pump Rebuild by ECU Testing.

I have just had this done and now my brakes feel very squishy and have long pedal travel. The brakes were amazing before! Normally this is to do with air in the system and I presume that is indeed what it is. The specialist who did the refit assures me that the system was bled manually and again with a computer to pump the abs module. They have asked me to see how it is in a week but if there is air in the system surely it's trapped there and is not going to purge itself?!

Please see attached video too where you can hear a rather concerning noise that certainly wasn't there before the repair work was done.

Thanks
Saul
 
<iframe src="https://player.vimeo.com/video/434084888" width="640" height="360" frameborder="0" allow="autoplay; fullscreen" allowfullscreen></iframe>
 
Is that noise really coming from the abs pump!? That is a funky sound.
No the air won't purge itself. The system must be bled properly. It is not a complex procedure so it surprises me if your garage has failed to do so.
I would send the video over to ecutesting and see what they make of it.
Have you confirmed the noise is coming from the abs pump? I don't see why it would come on if it hasn't detected a locked wheel during motion.
 
The noise only appeared after the repair was done and only happens when you depress the brake whilst stationary. Such a pain.
 
How exactly did they bleed them manually? I’ve worked on z4 brakes quite a bit and never had any success bleeding by ‘pumping’ the brake pedal. Every time I have had to use a pressure bleeder on the reservoir.

The process I would suggest is:

1) Initial pressure bleed out through all four calipers, starting with the one furthest away from the master cylinder in that order, finishing with the nearest.

2) DSC purge using INPA etc

3) Repeat step 1.

I’m 99% sure that will resolve your problems
 
The garage just Power and Manually re bled the brakes and got a few extra bubbles out. Pedal now feels nice and firm but the noise is still there whilst stationary and pumping the brakes...not that that is a natural thing to do. If anyone can sit in there car and pump the brakes 5 or 6 times and replicate that whirring noise please let me know. The garage are chasing up with ECU Testing.
 
Penelope said:
ECU Testing said the noise is normal. It doesn't do it whilst out driving about.
Click to expand...

I still don't think that noise is 'normal' be any means. Certainly I have never heard it!
 
ph001 said:
Penelope said:
ECU Testing said the noise is normal. It doesn't do it whilst out driving about.
Click to expand...

I still don't think that noise is 'normal' be any means. Certainly I have never heard it!
Click to expand...

They said it is the pump releasing pressure as when stationary it's not being used and pumping the brake whilst stationary is not something you would ever do naturally. The only reason I was doing it was to gauge pedal travel (which is now solid) Do you hear it if you sit there and pump the brake 5 or 6 times?
 
Penelope said:
ph001 said:
Penelope said:
ECU Testing said the noise is normal. It doesn't do it whilst out driving about.
Click to expand...

I still don't think that noise is 'normal' be any means. Certainly I have never heard it!
Click to expand...

They said it is the pump releasing pressure as when stationary it's not being used and pumping the brake whilst stationary is not something you would ever do naturally. The only reason I was doing it was to gauge pedal travel (which is now solid) Do you hear it if you sit there and pump the brake 5 or 6 times?
Click to expand...

...Definitely not. The pump shouldn't even be running unless the ABS / DSC is activated so what they say makes no sense.
 
I'll check if it does it with DTC button pressed as I understand that is suppose to disengage ABS amongst other things.


ph001 said:
Penelope said:
ph001 said:
I still don't think that noise is 'normal' be any means. Certainly I have never heard it!
Click to expand...

They said it is the pump releasing pressure as when stationary it's not being used and pumping the brake whilst stationary is not something you would ever do naturally. The only reason I was doing it was to gauge pedal travel (which is now solid) Do you hear it if you sit there and pump the brake 5 or 6 times?
Click to expand...

...Definitely not. The pump shouldn't even be running unless the ABS / DSC is activated so what they say makes no sense.
Click to expand...
 
Penelope said:
I'll check if it does it with DTC button pressed as I understand that is suppose to disengage ABS amongst other things.


ph001 said:
Penelope said:
They said it is the pump releasing pressure as when stationary it's not being used and pumping the brake whilst stationary is not something you would ever do naturally. The only reason I was doing it was to gauge pedal travel (which is now solid) Do you hear it if you sit there and pump the brake 5 or 6 times?
Click to expand...

...Definitely not. The pump shouldn't even be running unless the ABS / DSC is activated so what they say makes no sense.
Click to expand...
Click to expand...

I don’t think you can turn the abs off? Only the traction/stability control :?
Rob
 
To clarify... I mean the pump doesn’t run unless the car is actively dealing with a lock up (ABS) or applying brakes / cutting power (DSC). The pump doesn’t run during normal driving at all, irrespective of whether you have the button pressed or not.
 
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