Pontiac FIREBIRD 1972 Service Manual page 1172

STEERING 9-19
tips move inward. High pressure oil discharges into cavity
1, (Figs. 9-17, 9-1 8 and 9- 19), through two open ports in
the pressure plate, and through two blind ports in the
thrust plate, which are connected to cavity 1 by the cross-
over holes in the ring. A portion of this oil is circulated
through the central port system in the pressure plate,
forcing the vanes to follow the cam surface of the ring. The
ring-rotor leakage oil (12) is used for drive shaft bushing
lubrication and then bled to the reservoir.
SLOW
C O R N E R I N G
During slow cornering maneuvers (Fig. 9- 17), the oil pres-
sure required will usually not exceed 400 p.s.i. The speed
of the pump is not high enough to require internal bypass-
ing of oil, therefore, the pump by-pass port to (5) remains
closed. The high pressure discharge oil (7) is slightly lower
in pressure than the internal high pressure oil (1). The
drop in pressure occurs as oil flows through the flow
HIGH PRESSURE DISCHARGE
f
INTERNAL HIGH PRESSURE
RESERVOIR AND RETURN OIL
RING, ROTOR LEAKAGE OIL
Fig. 9-17 Oil Flow
-
Slow Cornering