Copyright by Goodheart-Willcox Co., Inc.
Chapter 9 Automatic Transmission Control Components 195
Vane
Rotor
Bore ring
Pivot pin
Pump priming
spring
Main regulator
valve is feeding
line pressure
into decrease
circuit at minimum
pump output
Main regulator
valve
Limited TV
Main regulator
boost valve
To hydraulic
system
Filter
Sump
Decrease
Line
Note: Bore ring moved to left
and pump priming spring is compressed.
Figure 9-11. At minimum pump output (low engine speeds), the pressure regulator valve keeps pressure from moving the pump.
Spring pressure keeps the pump in position to produce maximum output.
Vane
Rotor
Bore ring
Pivot pin
Decrease
Line
Pump priming
spring
To hydraulic
system
Filter
Sump
Main regulator
valve
Limited TV
Main regulator
boost valve
Exhaust
Main regulator valve
is opening decrease circuit
to exhaust at maximum
pump output
Figure 9-12. At maximum pump output (high engine speeds), the pressure regulator valve allows hydraulic pressure to work against
spring pressure to move the pump to its lowest output position.