2000 ranger brake issue, help please

[surveywaters]

My brakes will not lock up and it requires alot of effort to stop. I replaced pads, discs, shoes, wheel cylinders, and flush the fluid with no improvement. I have followed the instructions in the Haynes manual to check my booster and it passed all the tests. The pedal is hard right off the bat.

What's going on?

 

[adsm08]

Have you checked for crushed or pinched lines yet?

 

[rangerlocal]

I'm kind of having the same issue after rebuilding both front calipers, rear wheel cylinders, new pads all around. I keep bleeding. Still not quite right, but at least the truck stops now. Seem to get just a couple little more tiny bubbles out every time I crack the bleeder after running the truck around the block and hitting a few bumps and slamming the brakes a few times. I'm hoping after doing that a couple more times I'll have all the air out and the pedal will return to normal. Seems fine without the truck running. When started, it sinks pretty low. Brakes don't want to apply until the pedal is almost to the floor, then they grab decently well.

 

[adsm08]

I'm kind of having the same issue after rebuilding both front calipers, rear wheel cylinders, new pads all around. I keep bleeding. Still not quite right, but at least the truck stops now. Seem to get just a couple little more tiny bubbles out every time I crack the bleeder after running the truck around the block and hitting a few bumps and slamming the brakes a few times. I'm hoping after doing that a couple more times I'll have all the air out and the pedal will return to normal. Seems fine without the truck running. When started, it sinks pretty low. Brakes don't want to apply until the pedal is almost to the floor, then they grab decently well.

I am going to ask you a really dumb question. Don't answer it from memory, go look at the truck.

Are the bleeders at the top or the bottom of the caliper?

 

[rangerlocal]

Top. Double and triple checked every time I bled. I also kept all hardware on the same side of the truck I took it off of so that there wouldn't be any mix ups. Don't see any bubbles coming out anywhere when I bleed at this point. Still a bit spongy. The rears are adjusted up as well, although it seems the adjuster cable is always loose. Don't know if it's supposed to be slightly loose until the parking brake is applied, but I have the rears adjusted out correctly manually. Checked for leaks, and checked for swelling lines. Both fronts look fine. Calipers are grabbing as I can see them shift up slightly when the brakes are applied. Bearings and races checked, tightened, and repacked. Rotors resurfaced with plenty of meat left. Rear shoes extend when brake is applied as seen with the drum off before adjustment. No ABS light or Brake light illuminated.

Maybe they just need to "brake" in a bit? (See what I did there? )

 

[surveywaters]

I got mine fixed, despite running all the checks for a vacuum leak at the booster with good results, I replaced it and can stop on a dime now. Once all the work was done though, my ABS light comes on at 15mph and stays on whether I'm braking or not.

 

[rangerlocal]

Yours was hard with the vehicle running though correct? That is if I'm reading your original post correctly.

 

[surveywaters]

That's right, it was hard at about 1 1/2" of travel. The truck would stop but would not lock the tires.

SO today I change the differential fluid and cleaned the sensor on the top. It sill cuts the ABS light on at 15mph and it stays on until the truck is shut off. This has never been an issue and I didn't touch anything on the differential while changing the brakes. Is there another sensor somewhere?

 

[rangerlocal]

Did you have any part of the brake system open? If so, you may need to bleed your RABS unit, or just flush out all the old fluid if it has never been changed. It absorbs moisture over time and can really mess with ABS sensors.

Also, check the resistance of the ABS sensor at the back. It may need to be replaced instead of just cleaned.