Went out to do battle with this again today. The brakes were binding, as they were after the last time I rebuilt the them, so I drove that van up and down a bit to free them off and let everything settle into place (which worked last time). Didn't work this time. Melted all of the bearing grease into the drums. Excellent.
I dismantled both sides again and adjusted the actuator (as opposed to the adjuster) so that I had an equal gap between the shoe and the edge of the back plate at zero adjustment. Now both sides spun freely with the brakes off. Progress, or so I thought.
Adjusted the brakes, tested at full braking effect with this setup...
[IMG]
One side still brakes twice as much as the other side.
Adjusted again, and again, and again, no change.
I swapped the drums side to side, no change.
I swapped the drums and the shoes side to side. No change, in fact worse.
All shoes are the same thickness (well, to within 1,5mm)
The cable moves the same amount (to within 2mm) both sides.
The actuator in the drum moves by the same amount both sides.
[IMG]
I'm trying to think of more components to swap side to side. All that's left is the brake wire, the actuators and the adjustors. The adjustors work, so I think I can rule them out. Somethings obviously not working as it should under load. I'm wondering if the wire is stretching on one side under load, as opposed to pulling on the actuator?
If I "twang" the wires, they resonate with the same note, which should mean they have equal tension.
I'm considering adding a tensioner to each wire to allow for individual adjustment.
4 days I've been at this now and nothing to show for it.
EDIT/UPDATERING: Brake cables swaped from side to side. No change...