12. COOLING SYSTEM GRAND DINK 250 Remove the four bolts and the water pump Bolts Water Pump Cover cover, gasket and 2 dowel pins. Impeller (Left Hand Threads) Remove the water pump impeller. The impeller has left hand threads. Inspect the mechanical (water) seal and seal Mechanical Seal washer for wear or damage. The mechanical seal and seal washer must be replace as a set. Impeller Seal Washer (Porcelain) 12-10