I have a mate at Bendigo Brake and Clutch , Norm Brown 54423187 , give him a call and tell him Dennis Cope recommended you , if he cant help he will set you on the right path.
If you have checked Brake Linings for contamination ie Grease and are OK and Linings are not separating from the Brake Shoe Try the following:-
1.Loosen the Backing Plate to Axle securing bolts/nuts enough
2. Refit the Brake Drum Assy with bearings adjusted correctly
3. Adjust Brake Shoes tight into the Drum
4. Tighten all Axle/Backing Plate bolts as firm as possible
5. Back off Brake shoe adjuster
6. Remove Brake Drum assy
7. Recheck Tension of all Axle/Backing Plate bolts/nuts
8. Refit brake drum and adjust wheel bearings
9. Readjust brake shoes until drum nearly locked and Back Off approx 8 to 10 clicks
10. Brake drum should rotate freely with maybe a slight shoe scraping noise.
The reason for trying this is that the Backing Plates can sometimes move and this causes the Brake Shoe to Drum alignment to be incorrect.
I have had this happen twice on a new dual axle brake assy which when first fitted gave no sign of any lock up even after earlier Brake Testing sequences but a few 100 kms down the track they somehow moved causing problems. After carrying out this procedure all has been great since.
