Brake magnet scoring drum

At the moment, brake units, hubs and bearings are new.  Wheels turn about a complete revolution before stopping. Burnishing is not completed yet but drove about 20 miles with everything new and braking seems to be equal on both wheels.  On a side note, my part time mechanic worked on RV's ad a dealership for quite a few years and helped me with the problem.  He said that when you burnish new brakes, they need an initial adjustment that prevents the wheel from turning no more that one half turn.  When I called Lippert, they said the wheel should spin with just a slight resistance and you could hear a small amount of contact to start the burnishing process with.

Some scoring is normal, the magnets make contact with the drum surface when they are energized. It's the friction of that contact that activates the brake shoes.

But I'm not sure if what youre describing is normal or not. The contact shouldnt be producing metal shavings for example. Do you have any pics of the scoring?

A bad contact would make one magnet deenergize so that brake stopped making contact but it wouldn't cause scoring. Quite the opposite. I'd recommend getting rid of the insulation displacement connectors on the brake wiring and replacing them with butt splices or soldered connections and heat shrink tubing. The factory connectors are junk.   

Glad you have it sorted out now. For sure the burnishing process gets the brakes pretty darn hot.

If you do the math it works out that the drums will heat up by about 300 degrees above starting temp if you use the trailer brakes alone to fully stop the rig from freeway speed.

Lippert has you do up to 50 gentler decelerations from 40 to 20 and wants you to get the drums up to around the same 350-400 degrees. Safer and more controllable that way.

I carry my ir thermometer in my tow vehicle arm rest and check bearing and tire temps while refueling, and brake temps once in awhile after making a full stop from freeway speeds or after a downhill grade. Great tool which can give you early warning of several potential problems.

Thanks.  Amps with the car running.  L:.14, R:1.45.  While I see a big difference, still not sure about the measurement as I would expect the problem L site to be getting more not less than the R.  I'll test again with the battery.