R 2500 P/U 2WD V8-350 5.7L (1987)
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Vacuum Regulator Valve: Description and Operation
Manual Valve
Establishes range of transmission operation as selected by the vehicle operator through the manual selector lever.
1-2 Regulator Valve
Regulates modulator pressure to a proportional pressure, tending to keep the 1-2 shift valve in downshift position.