ABS fault when braking in reverse

[Lonne Mays]

When I'm backing the rig up into a tight space and applying the brakes to creep slowly, the chatter and groaning of the brakes on the front brakes cause the ABS to register and log a 4-1 and/or 4-2 code (faulty front axle left and/or front axle right ABS sensor wiring open or shorted).  This code can be cleared and the ABS light remains off until the next time I try backing up slowly and have the brakes chatter and groan.  Anyone else experience this or have any ideas for cures?  (I have inspected the wire to the sensors, and they all seem tight and good.)

[Fred Brooks]

   Hi Lonne,  Not an uncommon issue especially once the brakes have seated and are used to stopping the coach in that direction 98% of the time. If you could think of it as "grooves" on a record, they only want to go in one direction. No real fix for this except replace the pads and turn the rotors to a fresh surface. Mike or Gerald may have a suggestion that I am not aware of. Fred

[Richard Davis]

I am assuming you have drum brakes on all four wheels.  The chattering and groaning you describe is usually attributed to dirty "S" cams and rollers.  Removing the front drums and cleaning the cams and rollers should alleviate the issue.

Richard

[Lonne Mays]

Hi Richard,
I have disk brakes on all four wheels.  The system is air-over-hydraulic disk brakes.  The rotors are 16" diameter, if my memory serves me correctly.  When I had all six new tires put on this year, I had the opportunity to inspect and I was really impressed by the massive size of the disk brake rotors and pads on all four wheels.