Rear Brakes Adjustment Procedure: While I was at the mechanic to get the brake job done, the rear brakes gave him quite a bit of trouble. The adjuster has a small window to adjust from the outside but there is a ratchet which only allows the adjuster to be tighten but not loosened.
Adjuster is pictured. Note the ratchet which allows the adjuster to turn only one way.
The mechanic had to remove the drum each time he over adjusted this device. I had the work shop manual with me and pointed out the "right" way. But since he did not have the required tool, it had to be trial and error.
The correct procedure is really quite simple. Measure the drum from within:
I had to go buy this caliper to do the job properly
Rear brake shoe initial setup procedure
These brakes are supposed to be self adjusting. As the lining wears the adjuster advances automatically. How that happens is quite simple. Every time the brake is pressed, the pawl on the ratchet also moves a tiny bit. While the shoes expand and contract horizontally, the pawl moves vertically owing to the pin and spring mechanism. As the lining wears, the shoes have to move further out to contact the drum. This additional movement also causes the pawl to move a bit more than usual and in doing so engages the next step on the ratchet. Now as the brake pedal is released, the pawl returns to its resting place but this time it has already engaged the step in the ratchet hence turning the adjuster by one step. Simply brilliant.
So getting back to the van, the inside of the drum was measured to be 254mm. Hence the brake shoes need to be adjusted 1.5mm less that the drum. In this case the brake shoes outer lining needs to be 252.5mm apart.
The caliper is set at 252. Trying to get 252.5 proved to be a bit fidgety. I have used the 10cm line as the datum to avoid any error at the start of the measuring tape.
The next step is to take the caliper and check the brake shoes. Sure enough as suspected the shoes were too far out. I forgot to take a picture of me measuring the shoes. Nothing earth shattering to be seen .
Total time taken 15 min per side.
Van tested and happy to report that brakes no longer dragging.