SCHEDULED MAINTENANCE 1-11 COOLANT VISCOSITY MEASUREMENT Run the engine until the coolant is mixed completely, drain a little of coolant to determine the coolant viscosity at a safe operating temperature, measure the coolant viscosity and ad- just it to the specified value. REPLACING COOLANT CAUTION If the coolant is hot, injury can happen, so when the engine is hot, never open the radiator cap until the coolant temperature is dropped. When open the ra- diator cap, be careful of hot coolant or steam, sur- round the upper portion of the cap with a rag, slightly open it counterclockwise to drop the pressure through the reservoir tank tube, and then slowly turn the cap to open. 1.
After opening the radiator cap, loosen the drain plug and the engine drain plug and drain the coolant. 2. Remove the reservoir tank and drain the coolant. 3. After draining the coolant completely, close the drain plug, fill the engine and the radiator full with a radiator cleaner, and clean the engine and the radiator. 4. After completing the cleaning, drain the cleaner and close the radiator and engine drain plug. 5. After running the engine for a while, inspect the coolant level and add a coolant to the specified level. 6. Replenish the reservoir tank with a coolant until the level reads between FULL and LOW marks.