Something is obviously not right here. Just have to figure it out.
My thoughts so far on this problem you have.
For the bad side nearly all parts of the system are using the same braking parts for the handbrake and main brake. The shoe pivot point does not change so the shape of the shoe in the drum does not seem important. Like Varesecrazy said contamination of a shoe would show up for the main brake too.
I think adjuster problems was just a red herring.
The problem must be related to something that only alters the handbrake performance, like a bent cable, wrongly routed cable, or a binding cable. Is the cable having a sudden change of direction as it leaves the cable cover?
As far as I can understand this problem the hand brake lever force is disapearing somewhere on the bad side.
My thoughts so far on this problem you have.
For the bad side nearly all parts of the system are using the same braking parts for the handbrake and main brake. The shoe pivot point does not change so the shape of the shoe in the drum does not seem important. Like Varesecrazy said contamination of a shoe would show up for the main brake too.
I think adjuster problems was just a red herring.
The problem must be related to something that only alters the handbrake performance, like a bent cable, wrongly routed cable, or a binding cable. Is the cable having a sudden change of direction as it leaves the cable cover?
As far as I can understand this problem the hand brake lever force is disapearing somewhere on the bad side.