02 Sport Trac ABS issue

[spidermonkey1187]

Hey everyone,

Here is the exact discrepancy: While applying the brakes the left drivers side brakes seem to actuate erratically when the vehicle reaches about 2 mph. This happens in both forward and reverse. No ABS light or codes.

Ok now here is how it happened: While changing the front brakes I needed to compress the caliper. I did not open any part of the brake system at this point. I simple compressed the caliper and inserted the new brakes then installed the assembly back on the rotor.

I think that there may have been an air bubble in the caliper that may have been pushed up into the ABS module when I compressed the caliper. I noticed the problem as soon as I test drove the vehicle after the maintenance was completed.

Maintenance that has been performed since: R/R master cylinder, R/R caliper, Bleed brakes repeatedly on multiple occasions, removed caliper/rotor assembly and reinstalled to verify proper alignment/installation, read out all ABS lines to each wheel (IAW 2002 Wiring Diagrams from the Ford Motor Company), swapped left and right wheel sensors (swapped back) and ensured they were very clean during this process. I think that is it.

The problem still persists so we have pulled the fusable link for the ABS system until we can get this resolved.

Any help is greatly appreciated thanks!

 

[harrykon]

sounds like it could be a bad hub. I had the same problem. ABS seemed to kick in (pulse) as you come to a slow stop. a couple times I thought I was going to hit whatever was in front of me. the ABS sensor is completely isolated from the hydraulic fluid so I don't think your brake job triggered it. Just a coincidence..

there are plenty of threads in this topic, do some research before you commit to the hub solution, but if you do, it's not a hard job. I went with Timkin.

 

[spidermonkey1187]

Harrykon

You were correct. I went ahead and purchased new bearings and races for both sides as well as a bearing packing tool. Taking the left off didn't reveal any noticable degredation in the bearings but the right was definately contaminated. R/R bearings and races and everything checks good! Thanks for your help!