Transmissions: Automatic Transmissions: Pressure regulation

The primary regulating valve	The primary regulating valve regulates the value of line pressure in the transmission.
Line pressure variations	Throttle valve pressure is derived from line pressure and is applied to the spring end of the primary regulating valve to increase line pressure relative to accelerator depression.
Modulator valve pressure	Modulator valve pressure is directed to the lower end of the primary regulating valve, opposite to the regulating spring.
The governor	The governor is in two sections comprising the governor valve and its spring, and a bob-weight retained by a 'C' clip.
Governor pressure	Upward movement of the 1-2 shift valve allows fluid at line pressure to flow to the apply side of the front band servo.
Kickdown pressure	Kickdown pressure is supplied to the spring end of the 1-2 shift valve to force a 2-1 downshift under 'kickdown' conditions.

Topic	Summary