Hey guys... 2004 F150 5.4 4x4 140,000km. My brakes have been pulsating for awhile now. When I am going down a hill and apply my brakes, my truck shakes a lot and I feel it in my brake and my steering. So I just put on some new Motocraft rotors and pads (FRONTS) The mechanic took his time and we greased the caliper pins and all the fun stuff. I would say the brakes are better but still pulsate when I brake. We did not disconnect the calipers so bleeding was not needed. Fluid is clean & correct level. Could it be air in the line the whole time before the change or bad caliper? So be honest the ones we took off did not look that bad. The pads were pretty thick and the rotors seemed decent, couple of small grooves. The back looked good so I don't think they are the problem. Any ideas? I think I wll get a fluid flush / bleed this week and see if this fixes the problem.

 

I had a similar problem on my wifes sport trac and found it to be the wheel speed sensor wasn't registering causing the abs to pulsate. You may want to give that a look at, will warn you that the sensor is built into the hub and bearing so if that is it you may need a whole new hub assembly. Hope that helps!

 

Would I not hear the abs going on??? I don't hear the abs engaging at all.

 

Your abs works every time you hit the brakes, automatically adjusting the the fluid pressure usually at the master cylinder. It is designed to adjust the brake pressure depending on your speed to keep your brakes from heating up or locking. when the sensor fails it cant read the speed of the tire so it pulsates eratically. Normally the ABS light will come on with a failure but that is only if the electrical side fails. the problem I had was there is a tab in the hub that the sensor counts as it spins to determine speed. That tab broke so the sensor was reading faulty never giving an ABS light.

 

not that this is your specific problem, just what I have encountered with my own vehicle.

 

So I took off my rear tires about 30 min ago and checked them real good.. I figured it was my fronts that were really bad because they do all the stopping but after taking off the tires in the rear.. I should have done the rears instead but it's too late now. I will be buying need rotors/brakes for the rear and hope it fixes my problem. They had some nasty grooves and the pads were at about 1/4.

 

Hope that solves the problem for you