A hydraulic control system for vehicle includes: an engine; an oil pump driven by the engine; a clutch device brought into engagement to enable power transmission between the engine and drive wheels by delivering a pressurized fluid thereto, and brought into disengagement to interrupt the power transmission between the engine and the drive wheels by discharging the fluid therefrom; and an accumulator storing the fluid delivered to the clutch device. The hydraulic control system is configured to control the hydraulic pressure applied to the clutch device, to stop the engine while bringing the clutch device into disengagement upon satisfaction of a predetermined stopping condition, and to restart the engine while bringing the clutch device into engagement upon satisfaction of a predetermined restarting condition. In the hydraulic control system, a hydraulic circuit increases flow rate of the fluid flowing between the accumulator and the clutch device when the engine is stopped.

In one instance, disclosed herein is a pressure modulating clutch control assembly that includes: a valve assembly configured to apply a clutch pressure to a clutch device; a pressure modulation assembly in fluid communication with the valve assembly and configured to control a maximum pressure level that the clutch pressure reaches; and a modular relief valve in fluid communication with the valve assembly and the pressure modulation assembly, the modular relief valve forming part of a hydraulic feedback loop between the valve assembly and the pressure modulation assembly, wherein the hydraulic feedback loop is configured such that an increase in a modulation pressure of a pressurized fluid within the pressure modulation assembly causes a corresponding increase in the clutch pressure until the clutch pressure reaches the maximum pressure level.

In one instance, disclosed herein is a pressure modulating clutch control assembly that includes: a valve assembly configured to apply a clutch pressure to a clutch device; a pressure modulation assembly in fluid communication with the valve assembly and configured to control a maximum pressure level that the clutch pressure reaches; and a modular relief valve in fluid communication with the valve assembly and the pressure modulation assembly, the modular relief valve forming part of a hydraulic feedback loop between the valve assembly and the pressure modulation assembly, wherein the hydraulic feedback loop is configured such that an increase in a modulation pressure of a pressurized fluid within the pressure modulation assembly causes a corresponding increase in the clutch pressure until the clutch pressure reaches the maximum pressure level.