Just learned something else. A leak in the system may cause air to get into the pump. Coolant is used to lubricate the pump if air will damage to pump.
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here!
| Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors