Howdy!

Kinda long post, but wanted to provide some detail...

I just finished replacing my front rotors and pads on my 2004 SCAB 4X2. I took it for a spin after doing the driver's side, and everything was fine. I did the same after replacing the passenger side, and the ABS light came on and stayed on. When it came on the first time, I felt some sort of "buzzing" coming from the brake pedal before the light came on.

The truck rides fine: no pulsating or vibration during braking (the reason I changed them out in the first place), no pulling to one side or the other, the temperature of the calipers feels the same from side to side, no leaks that I can see, and it brakes smoothly.

The replacement rotors are standardBrembos, not cross drilled or slotted, and the pads are Carquest Blue semi-metallics.

I torqued all the bolts (caliper and bracket, spindle nut [about busted a ******** getting that one off]) to the proper torque. One thing I did notice when compressing the caliper pistons on the passenger side was that on the top piston, the rubber skirt/seal surrounding the piston was sticking up above the top surface of the piston, while the lower piston's seal was nice and retracted into the caliper body. As far as I could tell I got the caliper over the new pads and rotors properly.

I found a thread that identifies the toothed rings on the back of the rotors as being installed improperly:

http://www.ford-trucks.com/forums/6...light=abs+light

Sounds like this was a real PITA. I can check the reluctor ring on the rotor to see if there are any obvious cracks or flaws in the teeth, but that means taking the caliper and bracket off, removing the rotor, getting a new spindle nut, cotter pin, etc., etc.

Also found other threads that seemed to point to a bad ABS wheel sensor, or a bad wiring harness. It looks like these sensors are fairly inexpensive and easy to install. However, I hate to just throw parts at it without getting some more info on the fault code. Maybe I just got some crud on the sensor...

From what I've read, OBD II codes do not include ABS codes, so the Autozone folks won't be able to extract them (I called about 5 stores in my area and none had an ABS reader).

I figure that I've narrowed it down to the passenger side, since the light didn't come on after I changed the driver side rotors/pads.

Has anyone replaced one of these ABS sensors? Easy? Difficult? Do I need to take off the wheel and caliper, bracket, and rotor to get to the sensor?

Thanks.

 

I've done one on a 2000 4x4. IIRC, it fastened directly to the hub/bearing assembly. And was kinda pricey. And some places wouldn't just sell the sensor without the hub assembly. It will be easier to replace with the wheel off. Just trace the wire to the sensor.

 

Well, I broke down and got me a copy of AutoIngenuity with the Ford enhanced package that will read ABS codes (and others beyond the engine codes). I figure 3-4 uses of that will pay for it, since the dealer charges $100 to read the codes.

I extracted the following codes from the scan tool:
B1484: Brake Pedal Input Open Circuit
C1297: Wheel Speed RF Signal Fault

So RF is the front passenger side, I think. Can anyone confirm that?

I attempted to troubleshoot the C1297 code,over the weekend, using the service manual instructions to probe the harness and sensor side to get a current reading as wheel is turned. I had to remove the splash shield to get at the connector, which took some time. I didn't get any reading - 0 mA - so either the sensor is bad, or I didn't do the measurement correctly. I had a little trouble getting the probes of my multi-meter to make good contact with the pins down in the connector (the sockets on the sensor side were easy). So I either re-measure the sensor current or I just replace the sensor and see if that fixes it. Either way I have to remove the splash shield.

I will troubleshoot the other code this week, but I have to remove the air cleaner assembly to get at the ABS controller.

I found a couple of places online that sell the sensor:

http://www2.partstrain.com/store/?N=...294967260+2424
http://www.autopartswarehouse.com/se...7015+1616+5744

Would bleeding the brakes help any? I just pushed the calipers back in with a c-clamp without opening the bleeder screws when I removed the calipers. I've since learned that was probably not a good idea. That being said, I did the same thing on the driver's side and I didn't have any problems. Thoughts?

 

Finally figured out what the problem was: the sensor ring was pressed onto the rotor hub too far, so the gap between the sensor face and the sensor ring was too large. I'm getting a replacement rotor shipped, and the folks at Moss Motors (where I purchased the rotors) were really helpful.

I'd recommend checking the sensor rings on each rotor to make sure there's not an obvious difference in how far they're pressed down.