Replaced ABS/trac. module(HCU): How to bleed the system?

Discussion in 'SN95 4.6L Mustang Tech' started by slvr00gt, Feb 6, 2008.

  1. Shop manual specified three step process:
    1) Do normal brake bleed on 4 calipers
    2) Connect scan tool and follow procedure (???)
    3) Repeat brake bleed on 4 calipers

    My scan tool (www.obd-2.com ) doesn't seem to have any special procedure for it.

    Any ideas (other then taking car to the dealership) ?

    Thanks
     
  2. Pretty sure dealer scan tools are the only ones that will have ABS function. It shouldn't cost more than $50 or something, maybe less or nothing if you find a dealer who isn't a dick.
     
  3. My scan tool can connect to HCU computer and pull the codes. It was what helped me to figure out that my original unit was bad. It just doesn't seem to have any "special procedures"

    I want to try to avoid driving to dealership with brakes all mushy
     
  4. Did you bleed all the lines at the unit? Seems it would be a good idea to do that before bleeding at the wheels.
     
  5. I let too much oil out and some air got into master brake cylinder. I bled master brake cylinder, bled all four calipers again and everything seems to work ok. Brakes are tight. I drove through the patch of ice: ABS and traction control both work fine. I am still wondering whether this scan tool procedure is really needed?

    Also, I contacted the author of the scantool. He said he plans to implement this ABS procedure within 1-2 months.
     
  6. you either need a dealer scan tool, NGS, WDS, IDS, PDS. or else a ABS enabled aftermarket scan tool.
     
  7. Thats interesting that your scan tool lets you pull HCU codes but it does not let you do a ABS service bleed..

    What you will need to do is bleed the brakes normally and then find a shop with the scan tool that will do a abs service bleed..

    you may have a soft pedal even after a normal bleed once you drive the car to get it to the shop for the abs bleed because the abs system will test the system when you are driving and not using the brakes and may introduce some air into the service brakes..

    I suggest you pull the fuses for the abs untill the service bleed is done.