I wouldnt turn a brake drum. Ever. I wouldnt buy brake components for prevo from anywhere than prevo. If u do not send the hub with the drum for turning there is the possibility it will run out when reattached to the hub.
If u do not like it replace it. When u turn a drum u have to use oversized brake linings. Don't like that either.
When u do the brake linings on prevo the linings and shoes and hardware, its all seporate. Lots of labor.
Im not saying u cant I'm saying experience has taught me different.
Small cracks in the brake drum r common, small cracks. Saturated linings can be dried out with brake parts cleaner with great results.
Did u index the bearing retaining nuts before u loosened them so u r sure it goes back togeather correctly?
I'm thinking your disc brakes r different on the steer and the tag. Correct?? I think your year is one that has the brakes on your 3 axles all configured different. Bremse front, drum drive, rockwell tag.
If u pull the front rotor it is knorr bremse unlike the tag that's rockwell. Be sure to locktight the mounting bolts for the caliper bracket on the front if u do.
There is a gasket that goes with the inner seal on the drive hub. Were those screws tight? That could have been the leak. Do u have the replacement gasket?
When reinstalling the axle be sure to tighten the studs with the cones first.
These vehicles r the safest things on the road but u cant drive them like a car. They r so smooth they lul u into a false sense of security. If u make that mistake it could cost u severely. Idiots who stop on freeway entrance ramps should have their lisence suspended, indefinitely.