Okay so this is a long drawn out problem with my brothers truck. he has a lifted f150, 2005 with a 5.4, has 37's and 22's. stock brakes.

Never had a problem until about a two or three years ago. takes it in the mudhole and destroys passenger side wheel bearing. i know he fixed only that side, idk what all else he did but he never changed the driver side.

about a year ago the abs light started showing inside the cab and the brakes were screeching. Not so much as a noise screech but the screech you feel in the brake peddle when your tires lock up and the traction control takes over. It would only do that randomly when pushing the brakes. however it never affected the performance of stopping. The light would turn off and it would be fine. it was random.

About a month ago he was driving to work and his driver side wheel bearing goes out. Front driver side tire was leaning a little, brake disk was hitting the caliper. it was a mess. i ended up using a 1 inch impact to get the big *** lug nut on the front axle off. the nut had welded itself to the bearing. i thought i was gonna break the spindle but i did not. we ended up changing both front disk, calipers, obviously bearings and nuts. braking was better.

But still the abs. the light was on and it did that surge screech thing. How do we fix this. he has a 6 month old girl and he will barely put her in it. Just needs to be fixed. any help would be appreciated.

 

bump

 

come on mechanics!

 

it sounds like he is having issues with the wheel speed sensors. check over the wireing to make sure nothing is kinked or damaged from when he went mudding. also since he did go mudding look at the tone rings for the abs to make sure nothing got knicked or is packed with any mud rocks or dirt. filling in the gaps would mess with the signals for the abs and apply it as well. you can also unplug the sensors and backprobe them with a dvom and check to see if you are getting a fluctuating ac signal coming out of them. beyond these basic checks then you will need to bring it in to a shop to have it checked out further.

 

Okay here is an update. i drove the truck this morning. Brake felt really good. abs light did show the whole time. however once i got on to my driveway, which is rock with potholes and whatnot, the brakes started making that feeling again. any ideas?

 

ummmm any comments or diagnosis on what i suggested above^^^^

 

Wish I could help you! Only i'm having a similar issue.. I have no ABS sensors on any wheels but somehow I have ABS light on full time as well. Not sure if the replacement parts the last owner bought wasn't the correct ones but no wiring as well... I'm confused the same as you... Guess if I knew how to look and see if my truck came with ABS stock then I could fix it.

 

There has to be an intermittent breakdown in the signal to the ABS computer.

pappajohn's suggestion about mud in the tonewheels is highly possible! (that WOULD be nice, wouldn't it! ) Hey, either everything is packed with mud, or everything gets a good hosing down, soaking everything with water.

With mudding wire damage is possible. Sharp metal edges on computer wiring harnesses can make LOVELY intermittents that are LOADS of fun to diagnose.

A bad wheel bearing could make the sensor hit the tone wheel, damaging both.

It could be the ABS computer itself: rare but not unusual

An overcharging alternator or bad power to the computer can be intermittent and cause "cute" computer glitches.

Also: it might be rear ABS, especially if the truck doesn't pull when the computer is "ABS-ing " on whatever wheel. if it was one of the fronts it would have an obvious pull.