So despite the project reboot, it’s springtime, so house projects are still a distraction from the bus project. I did, however, manage to get the brakes fully operational. The bus has 4-wheel drum brakes, which added greatly to the complexity. Adjusting the brake shoes can only be accomplished through a 1/2″ hole in each of the brake drums; through this hole a geared wheel (perpendicular to the hole) must be turned to move the shoes closer to the inside of the drum. If the shoes are too close to the drum the brakes drag, too far away and the brake pedal travels all the way to the floor.
Compared to disk brakes, drum brakes have the advantage of being ‘self energizing’, as the brake shoes expand against the drum they wedge themselves in somewhat and provide a force multiplication. This makes the extra complexity worthwhile on a vehicle, like the bus, that lacks power brakes. Nearly every modern car has power brakes and 4-wheel discs now; but heavy trucks and ‘real’ buses still use drums.