Over the past few months I've been slowly replacing brake parts including new front pads, rear drums, 1 ton pads and wheels cylinders and finally booster and master cylinder. Was out tonight and decided to see how well she stops no. I applied the brakes fairly hard as if someone stopped in front of you. Truck stopped well and you could tell at least on tire was trying to lock up. After releasing the brake the abs and brake light came on for about 1-2 seconds then went off. Is this a sign the abs is on it's way out? Fluid levels are good.

Also the front seems to dip more than i remember but not sure if that's possibly due to the 4" skyjacker springs that i installed in February.

 

Not likely.
Could be something simple like a vacuum hose distorted by the G forces of the braking and dropping the vacuum switch for a second. Also could be a slight imbalance in the braking systems, front to back, or a bubble in the fluid, most likely rear circuit, that makes the balancing valve go one way far enough to trip the switch.

If you can reproduce the symptoms, either of the two faults I stated can be checked by disconnecting the switch (vac or balance) and seeing if the fault goes away.

Likely the actual fault is only a small fraction of a second in duration.

 

Mine does that once in awhile but it also happens when you jockey the steering wheel back and forth, like a 3-4 point turn or to full lock one way or the other. Then the next brake application, the pedal goes to the floor with no brakes and the lights come on.

 

Thanks, but i am curious if the balance is off do to the heavy drooping of the front end.

 

The balance gets off when one braking circuit (front or back) hits bottom on the master cylinder and the other circuit continues to build pressure. Usually it's caused by brakes out of adjustment, or an air bubble, but could be caused by a weak hose or leak. Also, just after the piston in the balance valve trips the switch, it hits a detent and stays there, locking the switch, so the odds of that being the problem are pretty slim.

If any of the wires involved were chaffed and grounded briefly, you'd get a blink on the lights also.

 

I'm probably gonna rebleed the rears and check pad adjustment. Hey, at least its no longer a gamble which way it's gonna pull when the brakes are applied!