Expansion Tank 6-speed SMG

The clutch solenoid valve (marked with ‘QPV’) is responsible for actuating the clutch in the SMG system. A faulty valve can cause problems with clutch engagement, such as shuddering, delayed and harsh engagement, or even a complete failure of clutch actuation.

The pressure accumulator is responsible to store the pressure of the hydraulic system for later access by the actuators. This piston type accumulator has two cells: one cell storing the hydraulic fluid and one cell containing a Nitrogen gas filling which creates the counterpressure. Both cells are separated by a moving piston. Typical symptoms of a faulty pressure accumulator are frequent and short pump cycles. If there is no more preload pressure left in the accumulator, the pump runs every few seconds, which ultimately leads to a consequential damage of the pump motor. Along with the pump motor, a faulty pressure accumulator is one of the most common causes of pressure build-up issues and is one of the few wear parts in the system that should be regularly checked and replaced if necessary.

We offer a brand-new replacement accumulator.