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      10-19-2011, 09:51 PM   #1
3Coupe4Me
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Drives: 2007 328i Coupe
Join Date: Aug 2010
Location: S.FL

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DIY: Replacing DSC Hydro Unit E90, E92

Sometime ago I got the dreaded ABS, Brake and DSC trifecta error while coming home from work but it went off after I restarted the car.



This intermittent fault continued on and off for some time afterwards until about a month ago it finally stayed permanently on. I decided to take the car to an indy mechanic and have the codes read. The fault cade came back as a "5DF0" code which is a faulty DSC Hydrolic Pump. The estimated cost of repair was $530 for the pump + 4 hours labor to fix it.

Having worked on all the cars I've ever owned I decided to tackle the pump replacement myself. I ordered the part from Tischer for about $100 less than the dealer and with a free weekend coming up I decided to do the job myself. The part that I was most worried about was bleeding the ABS pump which requires special software at the dealer to cycle the pump as part of the bleeding process. However I did some research and saw where you can cycle the pump using the old school method of stomping on the bakes on a slippery surface while driving at a slow speed. Well, I had such a surface on my nearly 100ft long gravel driveway which would affect nobody but myself if I somehow screwed up on bleeding the brakes correctly.

When the part arrived I was actually pleasantly surprised that it had installation instructions included from the manufacturer. Even though it should have been just a simple swap of the parts the instructions showed how to relieve the pressure from the brake lines and how to prevent the lines from loosing but a little fluid. Another surprise was that during the installation of the new pump I discovered that it was already bench bled from the factory and already had fluid in it.

In total it took only about 10 minutes to do the swap. The hardest part was bleeding the four wheels until the brakes were firm then activating the ABS using the method described above and then bleeding all four wheels again until the entire brake system was flushed with new fluid.

Here are some pics and a description of the steps

ABS PUMP LOCATED HERE


CLOSE-UP VIEW OF PUMP WITH THE INTAKE AN OUT BRAKE LINES REMOVED


PUMP REMOVED AND LINE CAPPED TO PREVENT FLUID LOSS


THE CAPS I USED


PUMP ASSEMBLY WITH CONTROL UNIT ATTACHED


OLD AND NEW UNIT SIDE BY SIDE



PREPARATION FOR PUMP SWAP.

I swapped just the pump and kept the control unit because it is already programmed for the car. If I had put in the new one i would have had to take it to the dealer for programming.






After all that work it was good to see this


I also tested the DSC, Start off Assist and Cruise Control and everything is now fully functional.

Here are the directions from the manufacturer.
Attached Images
  
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