Expansion Tank Seal Kit 6-speed SMG

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.

The pump relay is responsible to turn on / off the hydraulic pump of the SMG system. A broken relay causes the pump to fail priming. Without hydraulic pressure, the system cannot engage the clutch or change gears.

Pictures shown are for illustration purpose only. Fits only E46 models.

This sensor provides the speed signal of the transmission input shaft. The speed signal is required by the SMG control unit to control the transmission system, adjusting properly the shaft speeds before engaging and disengaging the different gears.