40056107 Mercury SCREW

Water Temperature Regulators (Thermostats)
Replace
Replacing your thermostats prior to failure is a recommended preventive maintenance practice because it reduces the chances for unscheduled downtime.Depending on load, a thermostat that fails in a partially opened position will cause either an overheating or an over cooling condition.If the thermostat fails in the closed position, it will cause excessive overheating. Excessive overheating could result in cylinder head cracking or piston seizure problems.If the thermostat fails in the open position, it will cause the engine operating temperature to be too low during partial load operation. Low engine operating temperatures during partial loads could cause an excessive carbon build-up inside the cylinder. This excessive carbon build-up could result in accelerated ring and liner wear.
Failure to replace your thermostat on a regularly scheduled basis could cause severe engine damage.Caterpillar engines incorporate a shunt design cooling system and require operating the engine with a thermostat installed.If the thermostat is installed wrong, the engine may overheat, causing cylinder head damage. Ensure that the new thermostat is installed in the original position. Ensure that the thermostat vent hole is open.DO NOT use liquid gasket material on the gasket or cylinder head surface.
Refer to the Service Manual for the water temperature regulator replacement procedure, or consult with your Caterpillar dealer. If replacing thermostats ONLY, drain the coolant from the cooling system to a level below the thermostat housing.Refer to the Cooling System Specifications in this publication for all information regarding Acceptable Water, coolant/antifreeze and SCA requirements, or contact your Caterpillar dealer for assistance.Cooling System
Make sure you read and understand the information in the Safety and Cooling System Specifications sections of this manual before you proceed with cooling system maintenance.
Add Extender (Long Life Coolant/Antifreeze Only)
Caterpillar Long Life Coolant/Antifreeze (LLCA) does not require the frequent Supplemental Coolant Additive (SCA) additions associated with the present conventional coolants. Only a "one time" coolant Extender is required.Extender should be added to LLCA after 3,000 service hours or two years, whichever comes first. The cooling system should be treated with .95 L (1 qt) of Extender for every 46 L (12 US gal) of cooling system capacity. A 15 percent over or under treatment will not create any cooling system problems.For more Extender information, refer to the Extender topic in the Cooling System Specifications in this manual.Drain/Clean/Replace Coolant (Conventional Coolant/Antifreeze Only)
Do not perform this maintenance until you read and understand the material in the Safety and Cooling System Specifications sections of this publication.
Clean/Flush the cooling system before the recommended maintenance interval if:* Coolant is heavily contaminated.* The engine overheats frequently.* Foaming is observed in the radiator.* The oil cooler has failed, allowing oil to contaminate the coolant.
Use of commercially available cooling system cleaners may cause damage to cooling system components. Use only cooling system cleaners that are approved for Caterpillar engines.
A good time to inspect the water pump, replace the thermostat, and replace hoses is when your engine's cooling system has been drained.Drain
Radiator cap (1), and radiator drain valve (2).1. Stop the engine and allow the engine to cool. Loosen the radiator cap slowly to relieve any pressure, and remove the cap.2. Open the radiator drain valve (if equipped). If not equipped with a drain valve, remove the block and oil cooler drain plugs. Remove the drain plug from the bottom of the water pump housing. Allow the coolant to drain.
Dispose of used engine coolant properly or recycle. Various methods have been proposed to reclaim used coolant for reuse in engine cooling systems. The full distillation procedure is the only method acceptable by Caterpillar to reclaim the used coolant.
For information regarding disposal and recycling of used coolant:Contact Caterpillar Service Technology Group:Outside Illinois: 1-800-542-TOOLInside Illinois: 1-800-541-TOOLCanada: 1-800-523-TOOLClean
1. Flush the cooling system with clean water to remove any debris.2. Clean and install all drain plugs and/or close the drain valve(s).
Fill the cooling system no faster than 19 L (5 US gal) per minute to avoid air locks.
3. Fill the cooling system with a mixture of clean water and Caterpillar Fast Acting Cooling System Cleaner. Add .5 L (1 pt) of cleaner per 15 L (4 US gal) of cooling system capacity. Install the radiator filler cap.4. Start and run the engine for a minimum of 30 minutes with a coolant temperature of at least 82°C (180°F). Stop the engine and allow the engine to cool.5. Loosen the filler cap slowly to relieve any pressure, and remove the cap. Remove the cooling system drain plug(s) or open the drain valve(s). Allow the cleaning solution to drain. Flush the cooling system with clean water until the draining water is clear. Clean and install all drain plugs and/or close the drain valve(s).Cooling Systems with Heavy Deposits or Plugging
For the following procedure to be effective, there must be some active flow through the radiator and the other cooling system components.Follow the same steps as outlined above, with the following modifications to steps 3 and 4:3. Fill the cooling system with a mixture of clean water and Caterpillar Fast Acting Cooling System Cleaner. Add .5 L (1 pt) of cleaner per 3.8 to 7.6 L (1 to 2 US gal) of cooling system capacity. Install the radiator filler cap.4. Start and run the engine for a minimum of 90 minutes with a coolant temperature of at least 82°C (180°F). Stop the engine and allow the engine to cool.Fill
Refer to the Cooling System Specifications for all information regarding acceptable water, coolant/antifreeze, and supplemental coolant additive requirements. Refer to the Refill Capacities chart in this publication for the capacity of your engine's system.1. Fill the system with the recommended coolant/antifreeze mixture.2. Start and run the engine with the filler cap removed. Allow the coolant to warm, the thermostat to open and the coolant level to stabilize. Check the coolant level. Add coolant mixture if necessary to bring the coolant to within 13 mm (1/2 in) below the bottom of the fill tube or the correct level on the sight glass (if equipped).3. Check the condition of the filler cap gasket. If the gasket is