I use my emergency brake pretty much every time I park in my other cars, but when I engage it on my Cherokee, it does little to no good. I could literally drive fairly easy with it on it's that loose. My question is, how do I tighten it? Assuming that's the problem of course.

 

first check your rear brake shoes. if they've still got lots of meat left on them, then you can adjust them by the star adjuster by going through the slot on the rear of the drum. sometimes has a rubber plug that has to be removed to gain access.

but if you have to adjust further, you can hopefully adjust the tension from the adjuster rod above the driveshaft under the e-brake handle.

but at least make sure the cables are in good shape and hooked up to the drum brake lever behind the brake shoes.

but chances are, you need new shoes and possibly drums.

 

Listen to this, it is a true statement.

This link will help if you end up doing the brakes

http://4x4xplor.com/drum-brakes.html