BRAKE SYSTEM CONTINUED
When the coil (Figure 20, Item 4) is de-energized, the plunger (Figure 20, Item 3) is returned to its seat by the
plunger spring. This movement seals off the air flow from the passageway (Figure 20, Item 2) and opens the
exhaust passageway (Figure 20, Item 7). The force of the spring on the spindle end overcomes the air pressure in
the diaphragm cavity causing the air to flow through the passageway (Figure 20, Item 5), around the plunger
(Figure 20, Item 3), through the exhaust passageway (Figure 20, Item 7), and out the exhaust port (Figure 20,
Figure 20. Cutaway of Air Solenoid Valve (Closed).
The steering gear is a recirculating ball bearing, worm and nut type.
The recirculating ball type gear consists of a ball nut connected to the steering worm and in mesh with the sector
gear through precision finished helical grooves in the worm. The ball bearings roll within these grooves when the
steering wheel is turned. There are two complete circuits using tubular ball guides to deflect the balls away from
their helical path at one end of the grooves and guide them back to the other end.