Low speed ABS activation (1 Viewer)

[mitchjohnson000]

I recently did my front brake pads/rotors, lower ball joints, and repacked the wheel bearings on my 1999 LC.

When I come to a stop (1-5mph), I can feel the brake pedal pulsing and what sounds like ABS activating. I have no ABS lights on. I'm a bit lost as to how to proceed.

So far I've cleaned out the front sensors again, and checked the ABS rings, which seem in good condition. I followed FSM for wheel bearings, and I double checked that they are tight (14lb preload). I've haven't been able to spot anything loose or incorrectly installed.

My question is could a bad wheel speed sensor cause this even though I don't have a ABS light on? Also, is there a way I can disable ABS to ensure that this is an ABS issue not something else? I don't want to start ordering $200 sensors before I'm sure it's the issue.

 

[JunkCrzr89]

I followed FSM for wheel bearings, and I double checked that they are tight (14lb preload).

What was your final torque on the adjusting nut?

 

[mitchjohnson000]

70 ft lbs ish.

 

[mitchjohnson000]

I think I'm going to start unplugging wheel speed sensors to confirm that it is an ABS issue. Then I'll fire up the techstream and try and get some speed readouts.

 

[JunkCrzr89]

I think I'm going to start unplugging wheel speed sensors to confirm that it is an ABS issue. Then I'll fire up the techstream and try and get some speed readouts.

Sounds like a good approach.

 

[mitchjohnson000]

I think I found the problem. Upper caliper bolt is gone. I'm must have forgot to use my torque wrench on it, now to find a replacement bolt.

 

[JunkCrzr89]

Consider yourself lucky!
M12 x 1.25 x 25 mm is the bolt size.

FYI: The front caliper bolts have been known to walk out if old bolts without loctite. See here: Alert Alert Alert Brake Caliper mounting bolts! Replace them when removed. - https://forum.ih8mud.com/threads/alert-alert-alert-brake-caliper-mounting-bolts-replace-them-when-removed.1184893/

 

[mitchjohnson000]

Ordered 4 new OEM bolts. Going to replace them all.

 

[JunkCrzr89]

Ordered 4 new OEM bolts. Going to replace them all.

 

[mystican]

might be stripped be careful

 

[FxFormat]

Consider yourself lucky!
M12 x 1.25 x 25 mm is the bolt size.

FYI: The front caliper bolts have been known to walk out if old bolts without loctite. See here: Alert Alert Alert Brake Caliper mounting bolts! Replace them when removed. - https://forum.ih8mud.com/threads/alert-alert-alert-brake-caliper-mounting-bolts-replace-them-when-removed.1184893/

Live in rust belt, that bolt is welded shut by salt, no need to loctite.

 

[mitchjohnson000]

might be stripped be careful

Fortunately it wasn't stripped, I just forgot to torque it.

Live in rust belt, that bolt is welded shut by salt, no need to loctite.

Haha true, it's a Oklahoma truck so its not too rusty yet. Gotta re-apply fluid film soon though....