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Soft brakes after ABS pump fix??

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highway1
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Soft brakes after ABS pump fix??

Post by highway1 » Fri May 12, 2017 7:21 pm

The garage re-fitted my ABS/DSC pump today (2007 Coupe) after it was re-built by ECU testing.

I have noticed that the brakes are now noticeably "softer" than before and there is more brake travel before they give any real braking effect.
If you really anchor on, there just as effective but, the extra travel and softer feel is a bit odd??

I went back to the garage a while later to get the mechanics opinion and he said that he bled them twice and maybe the repair/fix means the brakes feel different? I do vaguely remember someone on here saying that their brakes felt softer/different after the pump repair??

The only other thing the mechanic suggested was vacumn bleeding the brakes and see if that helps?

He mentioned that some cars have individual valves on the ABS to bleed the brakes but the Z4 doesn't and there is nothing on the diagnostic to initialise any particular process??

I hope someone can throw some light on this issue!!

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Ducklakeview
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Soft brakes after ABS pump fix??

Post by Ducklakeview » Fri May 12, 2017 7:33 pm

There is an actual bleeding programme in the diagnostic software which is designed to ensure all of the air is purged from the abs pump block. I'd get a mechanic who knows what he's talking about as his explanation is utter crap. Soft brakes mean either air or a faulty hose.

Mike

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GuidoK
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Soft brakes after ABS pump fix??

Post by GuidoK » Fri May 12, 2017 8:03 pm

Did you get new pads?
New pads can also give a softer feeling until they glaze up.

But that abs pump bleed procedure has to be carried out if the abs pump lines have been decoupled. The procedure is displayed in bmw TIS (and requires DIS or INPA).
TIS also says when replacing the abs pump, it has to be programmed (progman) but I dont know the exact specifics for that.
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

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MrPT
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Soft brakes after ABS pump fix??

Post by MrPT » Fri May 12, 2017 10:19 pm

You do get a significantly harder pedal after using INPA to activate the ABS pump, compared to just bleeding the brakes as you would normally do. The garage should really know to do this and have the correct kit.

Are you ok bleeding the brakes yourself? If you are, I would recommend you go for an early morning run and deliberately activate ABS a few times (which will be fun, anyway) and then re-bleed.
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
2006 Z4 2.5si: gone

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