Help: Crazy brakes pulling hard on 2006 2500hd

[ToyhaulerTom]

Looking for help on trouble shooting a brake pull. The truck stops fine from most any speed until slowed to about 7 m.p.h. The steering wheel then turns hard to the left, maybe a half turn. Other than this goofy deal, it stops and handles fine. I'm thinking ABS? Any suggestions?

 

[Chevy1925]

You have a bad wheel speed sensor up front or one going bad. Check your wheel bearings for play and check for stored codes in the abs computer.

 

[ToyhaulerTom]

You have a bad wheel speed sensor up front or one going bad. Check your wheel bearings for play and check for stored codes in the abs computer.

Thanks James,
I'm thinking along these lines, as I see nothing wrong with the hardware itself.

 

[Chevy1925]

I dont know why they cause that weird braking action when they start going like that and not every truck has it happen but every truck ive had come in with that issue turned out to have bad wheel bearings or a bad sensor.

 

[chevyburnout1]

At slow speeds like that the amplitude from the speed sensor is drastically reduced. So any wear or air gap at the sensor due to worn bearings can cause the signal to drop out low enough to cause the ABS module to think the wheel locked up. If this happens brake pressure gets reduced from that wheel and as a result the vehicle can pull to the opposite side due to full brake force being applied to that wheel. Seen it multiple times on customer cars. Half the time they aren't even complaining about the issue.

 

[Chevy1925]

At slow speeds like that the amplitude from the speed sensor is drastically reduced. So any wear or air gap at the sensor due to worn bearings can cause the signal to drop out low enough to cause the ABS module to think the wheel locked up. If this happens brake pressure gets reduced from that wheel and as a result the vehicle can pull to the opposite side due to full brake force being applied to that wheel. Seen it multiple times on customer cars. Half the time they aren't even complaining about the issue.

thats what i figured but Ben says the ABS should not be active at that low of speed so thats where i get

 

[duratothemax]

Does the pedal vibrate and sound like the ABS pump motor is running?

 

[Chevy1925]

Does the pedal vibrate and sound like the ABS pump motor is running?

no, generally when this issue happens its just a flat pull to one side or the other like a caliper is stuck accept it only happens the last few mph before you come to a complete stop below the threshold of the ABS cutoff point.

 

[ToyhaulerTom]

Does the pedal vibrate and sound like the ABS pump motor is running?

I do get a small amount of ABS vibration just before the truck stops. That's what led me to think ABS.

 

[duratothemax]

yeah, definitely a speed sensor problem....check the hub,

 

[TheBac]

Shouldnt he be checking the hub on the opposite side of the direction the truck pulls?

 

[ToyhaulerTom]

Shouldnt he be checking the hub on the opposite side of the direction the truck pulls?

Jacked it up today and checked both wheels for worn bearings. The right bearing was shot, so a new one was installed. Problem fixed.
I guess the bad bearing was causing the ABS sensor to give a bad reading, as all systems seem normal, although the new hub assembly came with a sensor, so its unknown if the sensor was also bad.
Thanks for everyone's help.

 

[Pure Diesel]

Good info guys. I only get this when I have my 5th wheel hooked up and have to stop kind of quick. This pulls to the left about the same as the OP. Going to check this out this weekend, also.
Thanks

 

[PACougar]

Just an FYI, when the gap gers to big it can cause a nasty induction into the abs computer and fry it. Ask me how I know