Haldex 2 / Haldex 3 AOC Rear Differential Oil Pump

If your AWD Volvo has unexpectedly left you stranded in slippery conditions, it's possible your car's AWD needs service.

Modern Volvos use a system called Haldex to engage the rear wheels when the front wheels start to slip. 

^{A cutaway diagram of the Active On-Demand Coupling}

This Haldex system relies on a multi-plate clutch in the rear of the car, also called the Active On-Demand Coupling (AOC). When the system detects front wheel spin, valves open and allow pressurized oil to clamp the clutch down, hooking up the rear wheels and getting you moving again.

The system relies on oil pressure as high as 80 bar (1100psi!) to cycle the hydraulic clutch, and just like any system that pumps oil around, regular fluid and filter changes are recommended. For Haldex, we suggest changing the fluid and filter every 50,000 miles

_{A clogged (and failed!) Haldex pump}

If fluid changes are neglected, the filter can start to get clogged and the Haldex pump has to work harder and harder until it eventually burns out: you'll suddenly get lots of front wheel spin, and when scanned the car will have pump error codes from the DEM, such as DEM-0006.

This Genuine Volvo pump kit contains a new OEM pump and new fasteners to install the pump. If you've burned your pump out, this will get you back on the road quickly.

Additional Keywords: AOC ALL WHEEL DRIVE DIFF AWD