abs pump

[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.