Hydraulic Pump - Isuzu Trooper 1999 Workshop Manual

Hydraulic Pump

The hydraulic pump is a vane-type design. There are two
openings at the rear of the pump housing. The larger
opening contains the cam ring, pressure plate, thrust
plate, rotor and vane assembly, and end plate. The
smaller opening contains the pressure line union, flow
control valve and spring.
POWER ASSISTED SYSTEM
Pressure Switch
When hydraulic pressure reaches 3650 350 kPa (530
50 psi), the pressure switch of the power steering pump
closes causing the Powertrain Control Module (PCM) to
actuate the idle air control valve, which increases the
engine rpm to prevent the overload-induced engine
speed slow down. The switch opens when hydraulic
pressure drops to 3150
2A–3
350 kPa (460 50 psi).
442RV006