865289 Mercruiser FITTING, Orange (90 Degree), Air

Checking Coolant Level - Using Coolant Sight
Level GaugeIf the engine is equipped with a sight level gauge on either the radiator, expansion tank, or heat exchanger system, the coolant level can be checked with the engine either running or stopped.Add coolant whenever the coolant level is in the LOW level range. A warning device will be actuated when the level is lowered to the unsafe operating level.
SIGHT LEVEL GAUGEChecking Coolant Level
With the engine stopped:1. Slowly turn the filler cap to the first stop and release pressure.
Be careful. If the engine is warm-steam may spray outward under high pressure.
2. Push the cap down; turn until the cap is released.3. Maintain level to base of fill pipe. The coolant requires expansion space as it is heated.
PROPER COOLANT LEVEL4. Make-up coolant should be one of the following, in the order of preference: a. Permanent anti-freeze and fresh water solution.b. Rust inhibitor and fresh water solution.c. Drinkable water.d. Any available untreated raw water-never salt water.(a) Must be used if engine is to be shut down in below freezing weather without draining the coolant. (b) Can only be used when the coolant temperature is above freezing, or if the coolant will be immediately drained after shut down during below freezing temperatures.(c) or (d) Should only be used as a "temporary fix". As soon as possible, return the system to either (a) or (b).Checking Water Temperature Gauge Reading
The water temperature gauge should normally register in the NORMAL range when operating. However, with some systems, as long as the coolant does not boil the cooling system is functioning properly.1. If the water temperature gauge continually registers near-or in the "HOT" range-without boiling, have the system checked to determine if the cooling system is functioning properly.2. Frequently check the water temperature gauge while operating. Be sure to note any deviation from the normal reading.3. Whenever the reading changes, investigate the cause and have necessary repairs made.Draining Radiator Or Expansion Tank
Whenever it is necessary to drain the cooling system for repairs:1. Shut the engine off.2. Slowly turn the pressure cap to the first stop and release pressure.
Be careful. If the engine is warm-steam may spray outward under high pressure.
3. Push the cap down and turn until the cap is released.4. Open the drain valve for the radiator, or expansion tank.Draining Complete Cooling System
(D379, D398, D399 Engines)
1. Drain the radiator or expansion tank.2. Remove the water pump drain plug.
COOLANT DRAIN3. Remove the engine block right rear drain cover.
COOLANT DRAIN4. Remove the drain plug from the elbow of the oil cooler.
COOLANT DRAIN5. Remove the drain plugs from the front of the left and right water shields.
COOLANT DRAINS6. Remove the front and rear drain covers from the left side of the engine block.7. Remove the drain plug from the elbow on the left side of the flywheel housing.
COOLANT DRAIN
COOLANT DRAINS8. Remove the aftercooler drain plugs.
COOLANT DRAIN9. If equipped with a marine gear oil cooler, remove the oil cooler bonnet drain plug.
COOLANT DRAIN10. Allow the coolant to drain.11. Install all drain covers and plugs. Close the radiator or expansion tank drain valve.Draining Complete Cooling System
(D346, D348, D349 Engines)
1. Open the radiator or expansion tank drain.2. Remove the left front elbow drain plug.
ELBOW DRAIN3. Remove the oil cooler bonnet drain plug.
OIL COOLER WATER DRAIN4. Remove the engine jacket water pump drain plug.
WATER PUMP DRAIN PLUG5. Remove the auxiliary water pump drain plug if so equipped.
AUXILIARY WATER PUMP DRAIN6. After draining, install all drain plugs.7. If equipped with a marine gear oil cooler, remove the heat exchanger drain plug.
COOLANT DRAIN8. Allow the coolant to drain.9. Install all drain covers and plugs. Close the radiator or expansion tank drain valve.Flushing Cooling System
To clean the cooling system, any good commercial radiator cleaning solution can be used. Follow the instructions included with the cleaner.The cooling system can be cleaned using oxalic acid and sodium carbonate as follows: 1. Fill the cooling system with a solution consisting of 2 pounds of oxalic acid or sodium bisulfate (Na HSO4) with every 10 gallons of water. (Mix 25 grams with every 1 liter of water).2. Start the engine and operate at operating temperatures for 1/2 to 1 hour.3. Stop the engine and drain the cooling system.4. Flush the system with clean water until the draining water is clear.5. Install all drain plugs.6. Fill with a solution consisting of 1/2 pound sodium carbonate crystals (Na2 CO3 10 H2O) with every 10 gallons of water. (Mix 6 grams with every 1 liter of water),7. Start and run the engine for 10 minutes.8. Stop the engine and drain the cooling system.9. Flush the cooling system with clean water.10. Install all drain plugs.Filling Cooling System
1. Add antifreeze, if required.2. Fill to correct level with water which is free as possible from scale forming minerals.3. Fill the auxiliary water pump tank, if the raw water system was drained. Open the raw water valve.
AUXILIARY WATER PUMP FILL PLUG4. Start and run engine for 10 minutes.5. Remove the pressure cap and check the coolant level.6. Add coolant, if needed, until coolant is to the bottom of the filler tube.7. Install the radiator or expansion tank cap.Fan Belts And Drive
1. Check belt wear.2. Apply a 25 pound (10 kg) force, perpendicular to the belt, midway between the driver and driven pulley and measure the belt deflection.
MEASURING BELT DEFLECTION3. If one belt in a set requires replacement, always install a new matched set of belts-never replace just the worn belt. If only the worn belt is replaced, the new belt will be carrying all of the load-as it will not be stretched as much as the