E brake only stops truck from rolling forward

Hey all, my emergency brake works fine when I am parked nose down; it prevents my truck from rolling forward. When I’m parked nose up, the e brake doesn’t stop the truck from rolling backwards. 2.3L 1993 ford ranger manual trans.

E-brakes frequently have a harder time preventing a vehicle from rolling backwards.
The first thing that I would recommend is to try adjusting the e-brake cable.
It is possible that just being able to apply more force when applying the e-brake will resolve the problem.

It might be worthwhile to remove the drums and blow out the dust, lubricate the self adjusters and the e-brake linkage and adjust the shoes out until they make contact with the drum and then adjust the cable. If the cable is dragging it may need lubricating.

This is a very common problem. I don’t think that I’ve ever owned any vehicle that had an E-brake or parking brake that worked as well in reverse as it did in the forward mode.