DRUCKMITTELSTEUERSCHALTUNG FUER EIN AUTOMATISCHES FAHRZEUGGETRIEBE

摘要

In a hydraulic control system for an automatic power transmission for an automotive vehicle, a line pressure booster valve is provided to boost the line pressure to be developed by the pressure regulator valve of the control system when a downshift is to be made from the highest one of the gear ratios in the automatic forward drive range to the higher one of the gear ratios in a manual forward drive range of the transmission system.