The pump pre-charges the oil inside the haldex assembly to allow the coupling to engage faster. This part is prone to failure on higher mileage cars or if regular maintenance in not performed. If your pump is faulty, you...
Your Haldex unit should be serviced every 45k KM
Haldex pump seal set
Drain Plug x 1
Fill Plug x 1
OEM High Performance Gear Oil (850ML) x 1