Pump Motor BMW E60 M5 E63 M6 SMG III

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.

The replacement part we offer is a brand-new OE upgrade with improved internal piston seals, resulting in significantly increased durability.

The internal gears of the hydraulic pump tend to wear mechanically and as a result the pump can no longer build up pressure. Our set includes new gears and metal seals that exactly match the original specifications and restore the function of the pump. In the process of overhauling the gear pump, we also recommend replacing the seals, which you can find here.

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. The relay in your car may have a different color.