ABS/Low speed lock up

[StevensWMR]

Just purchased another 2000 CCSB 4wd. This one has 5.7 abc. When under the 20mph area I guess when I press the brake pedal, as soon as it engages the brakes they lock up and jams to a stop. When highway driving I do not have this problem. But on my driveway, in my shop, anywhere I just slowly creep, they lock up as soon as pedal pressed. Suggestions please.

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[94burbk1500]

Does it still happen if you remove the ABS fuse?

 

[454cid]

Check for leaking gear oil on the back brakes. This doesn't sound like an ABS problem to me.... ABS doesn't lock your brakes it unlocks them.

 

[Joe Dirte]

If it's kicking on abs pushing pedal back at u its probly a rusty front spindles that's pushing the sensor too far from reluctor. Mine has same issue so i just pulled the fuse for now til i upgrade spindles. No adverse effects. Old mechanic told me to fix it, take sensor out of housing, clean around hole and put a thin tin washer in-between sensor and hub with a small bit of never seize.

 

[StevensWMR]

I scanned with my OBD2 reader and it said bad speed sensor left front. So i swapped the driver hub assembly and fixed perfect

 

[454cid]

I scanned with my OBD2 reader and it said bad speed sensor left front. So i swapped the driver hub assembly and fixed perfect

That makes no sense to me. A bad speed sensor should trigger the ABS, releasing the brakes, not make them grab really hard. Unless maybe instead of locking up the ABS thinks it's spinning faster than it is?

 

[94burbk1500]

That makes no sense to me. A bad speed sensor should trigger the ABS, releasing the brakes, not make them grab really hard. Unless maybe instead of locking up the ABS thinks it's spinning faster than it is?

Wanna drive my s10 in the rain? Bad speed sensor can absolutely do this, I'm just a cheap **** and my s10 is my beater, so I don't fix it.

 

[454cid]

Wanna drive my s10 in the rain? Bad speed sensor can absolutely do this, I'm just a cheap **** and my s10 is my beater, so I don't fix it.

On every stop in the rain, or just the first few stops? I don't doubt the brakes grab, I just don't see how it's an ABS sensor fault. I've never heard of the ABS increasing braking pressure, only decreasing it. It is the Anti-Lock Brake System, after all.

 

[94burbk1500]

Just

On every stop in the rain, or just the first few stops? I don't doubt the brakes grab, I just don't see how it's an ABS sensor fault. I've never heard of the ABS increasing braking pressure, only decreasing it. It is the Anti-Lock Brake System, after all.

Just the first few. I don't fully understand it either, my buddy who is a mechanic told me it was a speed sensor issue.

 

[StevensWMR]

I’m unfamiliar with brake systems myself so I dont know whether it should throw a code or not but I do know that the abs light would come on very often, and when it did my brakes would lock up and slam the truck to a stop every time i even “trapped” the pedal while slow cruising. When I reached about 50 and up it would sometimes make the light turn off but not always. The few times I noticed the light not on my truck braked like normal. But the hub assembly must have been so worn and dry the heat most likely caused the sensor to throw the code. But the brakes aren’t PCM controlled. So why it only locked up while the code was on I am AMAZED/CONFUSED