I've got a '98 f-150 2wd with 4 wheel abs. The problem I'm having with it is the abs pulses during normal braking. I've used the E-brake to stop and there is no pulsing and I've pulled the abs fuse to disable the abs and it does not pulse when stopping. I have about 90k on the truck. Ford wants to replace the calipers and rotors to fix the problem, but I don't agree with them for the simple reason that the rotors are straight and within spec. Does anyone know what the problem might be?

 

Most likely wheel sensors in the hub. Similar problem with other makes of vehicle.

Hub rusts slightly forcing the the wheel sensor away from the tone wheel. Causes a perceived vehicle speed drop of 5-10 MPH....so when slowing down prior to a stop the ABS activates.

Remove the sensors, clean them and the hub and that should hopefully restore normal ABS operation.

 

should also check for front wheel bearing play. this can cause the air gap at the sensors to change and show inacurrate readings to the abs module. may ba as simple as just adjusting wheel bearing preload.

 

This morning, there was a bad slush/snow and my tires are bad. When I apply brakes on my 2001 F150 4x4, there is a terrible shaking in the brakes and hardly any braking. My brakes have been working fine except for now (on the slippery conditions). It seems like the ABS might be doing this, but I would like to get some ideas. If I brake on dry road, it braked fine.

Thank you

 

unclesly,

Sorry to tell you, but what you just described is how ABS normally feels when braking on a slippery surface, your brakes are fine.

 

hey my problem was the same as suprarunner,

but i never considered it to be ABS because the light never came on. had new brake pads and rotors put in, new calipers, a visit where they did nothing but charged me 20 bucks, and now its being looked again. I brought it to another shop and just got word that they have to diagnos the problem with the abs, but is there reasonable cause that i should intervene and tell thim the info that has been told in this forum?
the problem might just be a sensor in the hub? i wish i knew this before, should have used the search key sooner.
anyway, will cleaning or replacing that sensor be expensive, and would it show up as bad on a diagnostic test?

THanks for the help - and suprarunner, did that sensor replacement solve your problem?