I have a 97 F 150 4.6 4x4. I've been trying to chase down a brake problem and I can't seem to figure out the problem. When going slow such as in a parking lot when I pull in and hit the brakes it almost feels like the pedal pushes back at me. The rear tires chirp like they're locking up and very touching most of the time I have adjusted them and recently the ABS light will come on sometimes. At a normal speed going down the road and stopping at a light or stop sign the brakes work fine. When I plug in my scanner to check the ABS code it tells me the right front wheel circuit. The bearings are new and the sensors are new with them as well. I recently just did the front brakes rotors and swap to the larger 7700 pound breaks because I thought it was the front. So now that I know the front are okay what should I check. The rear brakes have recently been done in the past few months with all new parts and wheel cylinders drums were also bought brand new and I had them turn because I thought they might be warped. I bled the whole system and ran 3 new bottles of brake fluid threw it to flush out the old. I'm really scratching my head here trying to figure out what could be wrong. I don't have anything pushing against the calipers creating back pressure and all new parts that I could put on related to the brakes have been replaced. What is the next step or what could be the culprit. I really want to swap over to a 99 rear end with disc breaks. The rear brakes have always given me troubles ever since I've owned the truck for the past 10 years. When I pull trailers or anything with significant weight the brakes just suck *** which is why I swapped to the larger in the front. It seems like the rear was doing most of the stopping until the swap that I just recently did but I'm still having the problem with the pedal feels pushing back at me. Any experience advice would be greatly appreciated I would like to throw money in the right direction instead of firing the parts Cannon. thank you for any help

 

I had some similar symptoms. Hesitation in the pedal at very slow speeds then extreme sensitivity on the brakes (chirping tires). At normal speeds it was fine. I fixed it by replacing the ABS EHCU with a used one I bought on EBAY!

 

If your pedal is the main source of the syptoms I would start to check around the pedal area (I.E.tha master cylinder and brake booster). you may find something there. I dont know exactly what could be wrong, but it may be a good point to start because those are the 2 items that make your brakes actually function.

 

What is an abs echu?

 

Sorry, Should read EHCU.
https://www.google.com/search?q=What...+f150+abs+ehcu

The EHCU consists of an Electronic Control Module (ECM) attached to a Hydraulic Control Unit (HCU). If
service is required, ECM can be replaced if inoperative. If HCU is inoperative, entire EHCU must be replaced
as an assembly.