Brakes surging while driving. Peterbilt 348. Help!

Your problem is the traction control. If the ATC light is on then a technician should be able to solve the problem.

What you described sounds like what I get when I take a certain curve in Idaho a little faster than the truck approves of. It’ll go in panic mode and jack the brakes a couple times.

 

I’m definitely no mechanic, just sounds the same as mine. But mine is functioning properly.

I’m guessing it’s probably whatever sensor or gyro that measures how much you’re leaning in the curves.

 

Insite is diagnostic software for the engine. It most likely will not read much of anything off the rest of the modules in the truck, which are the ones you need to see the information off of.

 

Traction control works off of the ABS sensors that monitor each wheel. If a wheel is locking up the sensor notifies the controller/valve to release/pulse the brake application. If it senses spinning then it will apply/pulse the brake. Check all your wheel seals to make sure they are not leaking. If you have a wheel that is loose, as previously mentioned by Goodysnap, then a seal would most likely be leaking. Also check the wires from the sensor at each wheel back to the valve. Make sure that none of the wires rubbed anywhere and that none of the connections are corroded.

 

I have ran into this. Mostly after an engine software update. Every time the unit has active ABS/TCS lamps on. You didn’t mention any active faults/ lights?

The ESC parameter will become enabled in Bendix. Disabling it corrected the issue.
You really need Bendix A com. Assuming it’s a Bendix equipped truck which 95% are.

 

To Goodysnap: Post #2 from OP has a pic of the light.
OP: you need to get the code/s otherwise you are only guessing. Any codes will point you or a tech in the right direction.