abs pump

[adam1985]

the pump looks like a bastard to remove

Not 100% on the M but its pretty easy on the 3.0si had it out in less than an hour
I used this method for my non m coupe https://www.instructables.com/id/BMW-Z4 ... e-removal/

[srhutch]

the pump looks like a bastard to remove

Not 100% on the M but its pretty easy on the 3.0si had it out in less than an hour
I used this method for my non m coupe https://www.instructables.com/id/BMW-Z4 ... e-removal/

No different.

Out from wheel well, easy enough job. Just make sure you keep the brake pedal fully depressed before you remove and until it’s replaced otherwise there will be a ton of brake fluid lost.

Also cover the chassis supports with a rag and one removed clean with APC or similar to ensure no brake fluid is left to eat into the paint/protection.

[Vanne]

and then as in like frikkin virus, the ABS pump on my Z3 pull the pin.

[ph001]

Feckin typical! It is just the brushes on the motor sticking (the motor drives the ABS pump). It's a bit of a s**t design really as the motor only ever runs when DSC or the ABS is activated. For people that drive like miss Daisy it's not hard to understand why it fails after a few years.

My top tip - take the car on to some wet grass or gravel on occasion and exercise the ABS / DSC. Keeps the brushes clean.

[tom21]

Hi guys, just an update. Sent the abs pump off to ECU testing as recommended. This has fixed all the lights and all seems to be working well again. Traction control is back and ABS working again

ECU testing provide a great service at a fraction of the cost of sourcing a new abs pump. What a brilliant service.

Now to the bad part.....

My brake pedal is now feeling significantly "spongier" after coming back from the garage. I am slightly worried that they have used inferior brake fluid when bleeding the brakes. I am using a stoptech trophy big brake kit. Can anyone suggest some good fluid that works well with my uprated brakes? Also think its time for some new pads as they are quite a few years old now. Interested to hear what people use with these brakes for a fast road setup. Thanks

[MrPT]

Doubt it will be the fluid causing the sponginess. It’s more likely to be air in the system, i.e. they didn’t do a good job of bleeding.

Common oversights are not bleeding both sides of multi-pot calipers and not going through a thorough ABS bleed procedure when replacing the pump and/or fluid.

[ph001]

Bet they haven’t used the proper procedure. Needs to be done through INPA, basically you just press a button and it does all the priming of the DSC for you. Then you bleed the brakes in the conventional way. You will never get all the air out otherwise.

[tom21]

OK, I think I will take it to a more specialised garage for them to bleed the brakes for me. Im not too far from redish motorsport in bristol.

[Spaniarduk]

Bet they haven’t used the proper procedure. Needs to be done through INPA, basically you just press a button and it does all the priming of the DSC for you. Then you bleed the brakes in the conventional way. You will never get all the air out otherwise.

*just* what i was going to say

[adam1985]

Bet they haven’t used the proper procedure. Needs to be done through INPA, basically you just press a button and it does all the priming of the DSC for you. Then you bleed the brakes in the conventional way. You will never get all the air out otherwise.

Or you can go for the more redneck approach of bleeding normally as best you can. Take it for a test drive and activate the abs pump by an emergency stop on gravel and it should have pumped the air out of the abs unit. Then bleed the brakes again as normal.
Not as good as INPA method but it doesn't need any special software.

[srhutch]

Bet they haven’t used the proper procedure. Needs to be done through INPA, basically you just press a button and it does all the priming of the DSC for you. Then you bleed the brakes in the conventional way. You will never get all the air out otherwise.

Or you can go for the more redneck approach of bleeding normally as best you can. Take it for a test drive and activate the abs pump by an emergency stop on gravel and it should have pumped the air out of the abs unit. Then bleed the brakes again as normal.
Not as good as INPA method but it doesn't need any special software.

How does that work with a closed system. Why would the air move out of the ABS pump?

[BMWZ4MC]

Doubt it will be the fluid causing the sponginess. It’s more likely to be air in the system, i.e. they didn’t do a good job of bleeding.

Common oversights are not bleeding both sides of multi-pot calipers and not going through a thorough ABS bleed procedure when replacing the pump and/or fluid.

Bet they haven’t used the proper procedure. Needs to be done through INPA, basically you just press a button and it does all the priming of the DSC for you. Then you bleed the brakes in the conventional way. You will never get all the air out otherwise.

This

[adam1985]

How does that work with a closed system. Why would the air move out of the ABS pump?

Good point, I'm not entirely sure i presume that the pressure exerted by the pump is sufficient to force the air out of the pump into the brake lines. Your right in a closed system without a loop it doesn't sound like it should work.

When I had my ABS pump repaired about 5 years ago I didn't have INPA I refitted the pump and bled the brakes till no air came from any of the calipers. I, as the OP does, had a spongy pedal, assuming there was air still in there I bled again with my pressure bleeder but there was no air, i ran nearly a litre of fluid through the system with no air bubbles.
Still I had a spongy pedal, I saw the suggestion of activating the ABS pump on another forum and gave that a try then bled the brakes again and air did come out this time. So i can only assume that the air was in the ABS unit.

I had to get my ABS pump repaired again this august, ECUTesting to be fair to them repaired FOC under their warranty. This time I had INPA and did the proper bleed procedure and no spongy pedal first time.

[Lower]

Same for me. Spongy brakes after bleeding without activating the ABS pump.

Deliberate hard use of the throttle (traction control) and hard braking to activate the abs pushed the air out of the abs pump and a second bleed delivered a firm peddle again.