Grabby front brakes

[metalmike]

About 8 months ago I had my driver side wheel bearing replaced along with new pads and rotors. Recently, if I put any sort of pressure on the brake pedal my abs will kick in and my truck will stop short. The pedal will also flutter randomly while I'm braking. It's starting to get pretty bad so I could really use some "expert" advise here. Thanks.

 

[Earl43P]

Loose caliper bracket bolt
warped rotor
worn pad(s)
bent slider pin or needs greased
one of two pistons working (one stuck) in that caliper
bent caliper bracket

The list goes on and on.

Disassemble and inspect
Swap rotors side to side, see if grabbing moves with the rotor



I'll also say that virtually EVERY brake job I've ever done that had grabby front brakes needed to have the rear shoes replaced or adjusted. Every blessed time.

You can tell that is the case by depressing your parking brake down until you feel it slightly dragging, then use the pedal brake and note a higher pedal and smoother decel/stop.

There is a slight chance that one of your front ABS sensors is bad. Those usually show up at parking lot speeds, while braking and turning.

 

[FlyinRyan]

Sliders always seem to stick for me. My Dad had the same issue on his '06, ended up being wheel bearings. Were they fixed/torqued properly?

 

[metalmike]

I had the bearing put in at a Ford dealer, so I'll assume they did it right. I haven't replaced anything on the rear brakes, so my guess is I'll need a new set of shoes.

 

[zekew64]

I'm thinking that it very well could be one of two causes: a malfunctioning ABS modulator, or a malfunctioning Vehicle Speed Sensor. Either of those can cause your ABS to kick on and off, especially since you've had issues with the pedal fluctuating when you go to brake. Also, check the gear ring where the VSS is, and make sure those are in good condition; if there are any missing teeth, replace them.

The last thing would be, check your brake fluid. If the color isn't clear, check it with a Digitial Volt/Ohm Meter (DVOM). Set the DVOM to millivolts or volts (depends on the model, but it will say if the range can be selected or not; some DVOMs do the range automatically). Next, take one of the probes and put it into the brake fluid, and the other on the master cylinder casing; if the reading you get is 0.3 volts or higher, flush your brake fluid. The reason why you would have voltage in your brake fluid is because water still, through heating and cooling, condenses on the inside of the lines. If your fluid is bad, it won't hold pressure.

Also, make sure there is no air in your lines either. Hope this helps.

 

[dankhimself]

I had this same problem after the same service once, i readjusted my wheel bearing and bled my fronts, it went away, only thing i think it could have been was the wheel bearing being loose. My problem was only the abs kicking on when braking. The fluttering you are feeling sounds like abs too.

It was wierd that it went away when i did that stuff, but it is possible that the bearing was misadjusted, causing the reluctor ring(on the rotor) to be too far away from the abs sensor sometimes? it was very weird.