Hi. I have been help here before and hope to find a solution again. Last week I was changing rear differential fluid on 98 ram 2500 diesel rod. While doing it find to bolts under the cover were loose. They kind of located on left side when you look at a differential. I tighted them , put a cover back refill a case. Since then I have my brake light on. Are they supposed to be loose? How that affect brake? Need help please, any advise what was it?

 

What year is your truck?

The bolts are not supposed to be loose, and they shouldn't have any effect on the brakes. It's possible you bumped the rear wheel speed sensor, or it's connector. Might be worth re-checking that.

Is the ABS light on as well?

 

ABS off just a break. Dodge 1998. Is a wheel speed sensor in a differential?

 

The speed sensor is on top of your rear differential and has a couple of wires going to it. It reads the tone ring behind the ring gear in the differential.

 

thank you I will check it.