Operation CHARM: Car repair manuals for everyone.

Hydraulic System




Hydraulic System


Pump

The transmission uses a gerotor-type design front pump support and gear. The pump provides the volume of transmission fluid needed to charge the torque converter, main control assembly, cooling system and lube system. Pump pressure is regulated by the main regulator valve. The pump has an internal boost circuit which is more efficient at lower engine speeds.


Transmission Fluid Filter

All transmission fluid drawn from the transmission fluid pan by the pump passes through the transmission fluid filter. The transmission fluid filter and its accompanying seal are part of the transmission fluid path from the sump (transmission fluid pan) to the pump.


Main Control

The main control valve body contains 3 electronic solenoids:

- Two shift solenoids
- One Torque Converter Clutch (TCC) solenoid


Accumulators

The transmission uses 2 accumulators:

- 1-2 Accumulator - The 1-2 accumulator is used to soften the 1-2 shift by absorbing some of the pressure directed to the intermediate clutch. Constant line pressure is applied to the middle section of the 1-2 accumulator piston, opposing the intermediate clutch pressure, until the pressure is high enough to overcome line pressure. The top of the piston is exhausted to the sump.
- 2-3 Accumulator - The 2-3 accumulator is used to soften the 2-3 shift by absorbing some of the direct clutch pressure. Forward clutch pressure is applied to the top side of the 2-3 accumulator piston, holding the piston down until clutch pressure is high enough to overcome it. The middle section of the piston is exhausted to the sump.