ABS and Advance track lights go on and off, but sometimes not always the front brakes feel like the are locking up (actually feels like the wheels are gonna fall off) replaced the sensor (in the back) that was showing up on the computer ...now same sensor showing up

1. I would not be concerned because if there was a failure in the ABS you would definitely get an ABS warning light and the ABS and most likely the stability control/traction control systems (with added warning lights) will all switch off .

2. You can test if the ABS is operational. On a very quiet damp surface, straight, wide road( with NO other cars around), apply your brakes hard from a very low speed - up to 20 mph ONLY driving in a straight line - until the car stops. The front brakes should attempt to lock up under hard braking and if the ABS is operational you will feel it kick in and the brake pedal will pulsate as the ABS constantly allows brake pressure and then releases it to prevent the wheels from locking up on the damp road. If the ABS does not kick in be ready to release the brake pedal quickly to allow the wheels to rotate so you can steer the car safely. Without the ABS the front wheels should begin to lock up on the damp road surface due to the low level of tire grip. ONLY test this at very low speed and ONLY when driving in a straight line on a straight section of wide road with no other vehicles around.

I had the same problem with my 2002 Silverado. The grease seal on the right front wheel bearing went up letting grease build up on sensor . Disconnect ABS sensor wire at wheel one wheel at a time. Abs light on dash will come on but that's ok. drive and stop easy with wire disconnected until brakes feel normal. Then you will know wheel is the problem.

sounds like you have a abs sensor failing to read a signal on one wheel , car thinks that the wheel has locked up and as you press the brake it cuts the abs in and tries to release the brakes which is the noise your hearing and poss pulling to one side as you brake untill computer recognises a fault and shuts down the abs system which is when the abs light comes on, this pulling may indicate which one is faulty, it will need a abs sensor or signal ring on the drive shaft,usually a front one ! a damaged wheel bearing can cause an interupted signal to that sensor, failing that your abs pump is faulty, hopefully not the pump as this is very expensive

did you check the speed sensor on the rear end on top of the rear end. this sensor works the speedometer the abs and break lights and power door locks

The "pulsating" you refer to is Normal for a vehicle with ABS (Anti-Lock Brake Systems). It keeps the vehicle braking in a straight line and monitors each wheel with a sensor as to how fast it's turning while braking. The "pulsations" you feel is the ABS Computer turning each individual brake on and off to prevent a lock-up or skid. Perhaps if you road test the vehicle and apply your brakes lightly as in coming up on a stop sign in a residential neighborhood, you'll feel what you consider to be, "normal braking." Pulsations usually come at higher speeds and as to how much pressure you're putting on the brake pedal. You're safer than most now knowing that braking, even in snow, rain or gravel, that your vehicle will stop in a straight line instead of sliding to one side or the other.

If unhappy with ABS Braking, you can always remove the fuse to the ABS computer rendering it inoperative, so you have both choices as to what you'd like to do, right here.

I hope this helps,

~00 Buck~

"Still Living on the Right Side of Dirt..."

Sounds like you ABS system kicking in. This could be caused by a faulty wheel sensor or a cracked sensor ring which will either be mounted on the CV shaft or it will be part of your wheel bearing assembly. Or you actually locked up one of your wheels on wet or slippery pavement, in this case that would be normal.

That "grindy" feeling is when the ABS kicks in. It's only suppose to activate when you slam on the brakes and the wheels would normally lock. Instead, ABS will very quickly pump the brakes on and off, to prevent the wheels from locking (making a giant skid mark) and stopping the car more effectively. Generally this only happens if you slam on the brakes or loose traction due to rain or snow while braking. If this is happening often and the brake light is on, on the dash, then you need to get this checked out by a qualified mechanic ASAP.

It's possible it's the ABS brake sensor is faulty. The sensor attaches to the brake caliper. The only way to verify if the ABS is functioning is to test them in a skidding situation which is unsafe. Normal braking would not give any indication if the ABS is functioning. You shouldn't automatically assume they are functioning and should get the car checked out at a shop that features free checks. Best of luck.
Greg

Could possibly have a bad connection on a wheel speed sensor. This would cause an erratic reading making the ABS light come on because the system thinks a wheel is either slipping or dragging.

ok im going to go threw the list of overall problems with electrical
alternator wareing out you might not know but your alternator was used from before overhaul this could have been a problem before other problems replace this

now seperate problems down the list
power windows- you had overhaul done and i hope the mechanic marked the electrical lines the relay junction box if not then he got a relay wire crossed with another wire

steering bars for vehicle can be worn have checked by mechanic

abs lights- faulty sensors bad or worn hardware warped rotar bad bearings
always do either front together or back together brake install or all at same time with brake installs never do a side of brakes this throws the whole vehicle off its running smooth and stopping smooth

a/c this comes back to the relays in relay compartment this could have been switched with door relays you need to have the wireing checked for this

the brakes alone are by self there own problem so yes these are seperate problems

you will want to get a computer diagnostics and a free brake inspection at any brake master i found that they do more than just brakes and its really helpful in diagnosing problems for free then telling you what you need keep in mind brake masters
i hope this helped seeing that im not actually there in person to see vehicle