Every now and then when I start my truck, my ABS and Brake lights will stay on. I can drive around all day long and theyll stay on. But I can quickly turn the truck off and turn it back on and theyll be off. Is this just a bad ground somewhere causing them to do that? Or is this something I should be worried about?

 

It could be a lot of things , only testing would tell .
Sometimes just some maintenance will clear up things , flush break fluid from all wheels , blow compressed air around wheel sensors .
Its best , before digging into a problem to do maintenance on any system when looking for problems , besides clearing up , sometimes , you might find the cause when doing .

 

For the last couple of months, I've had the dang lights come on maybe once per 20 trips. They don't stay on after the start, they just come on at some point.

I've topped off brake fluid, I've examined all the wheel cylinders, I've whacked a few things with a crescent-hammer and cursed.

They'll stay off for days at a time, then it'll happen again. Anymore, I've taken to just doing a full inspection once every couple of weeks and calling it done.

Something somewhere is leaking just a bit now and then. When I find it, I'll let you know.

Regards, DBF

 

ABS and brake light also comes on on low vacuum. Check the vacuum switch on the drivers side fender near the cowl. You might just have a leak in that hose or a loose connection.