34505 Mercruiser SCREW, WATER PUMP TO CYLINDER BLOCK (7/8"0

Drain the Cooling System
Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Cat Dealer Service Tool Catalog" or refer to Special Publication, PECJ0003, "Cat Shop Supplies and Tools Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Stop the engine and allow the engine to cool. Ensure that the engine will not start when the cooling system is drained.
Loosen the cooling system filler cap slowly in order to relieve any pressure. Remove the cooling system filler cap.
Illustration 1 g00797171
Locations of the drain plugs
(1) Jacket water pump
(2) Cylinder block
Open the cooling system drain valves (if equipped). If the cooling system is not equipped with drain valves, remove drain plugs (1) and (2). Allow the coolant to drain. Note: If equipped, be sure to drain the heater and any related supply and return lines.
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 the disposal and the recycling of used coolant, consult your Caterpillar dealer or consult Dealer Service Tools Group:Inside USA 1-800-542-TOOL
Inside Illinois 1-800-541-TOOL
Canada 1-800-523-TOOL
International 1-309-578-7372
Flush
Systems Filled with Cat ELC, Cat ELI, or a Conventional Coolant that Meets the Cat EC-1 Requirements and the Standards of ASTM D6210
Flush the cooling system with clean water in order to remove any debris.
Close the drain valve (if equipped). Clean the drain plugs. Install the drain plugs. Refer to the Specifications Manual, SENR3130, "Torque Specifications" for more information on the proper torques.
Fill the cooling system no faster than 19 L (5 US gal) per minute to avoid air locks.
Fill the cooling system with clean water. Install the cooling system filler cap.
Start and run the engine at low idle until the temperature reaches 49 to 66 °C (120 to 150 °F).
Stop the engine and allow the engine to cool. Loosen the cooling system filler cap slowly in order to relieve any pressure. Remove the cooling system filler cap. Open the drain valve (if equipped) or remove the cooling system drain plugs. Allow the water to drain. Flush the cooling system with clean water. Close the drain valve (if equipped). Clean the drain plugs. Install the drain plugs. Refer to the Specifications Manual, SENR3130, "Torque Specifications" for more information on the proper torques. Systems Filled with Cat DEAC, Conventional Coolant which does not Meet the Cat EC-1 Requirements, or Supplemental Coolant Additive (SCA) and Water
Flush the cooling system with clean water in order to remove any debris.
Close the drain valve (if equipped). Clean the drain plugs. Install the drain plugs. Refer to the Specifications Manual, SENR3130, "Torque Specifications" for more information on the proper torques.
Fill the cooling system no faster than 19 L (5 US gal) per minute to avoid air locks.
Fill the cooling system with a mixture of clean water and Cat Fast Acting Cooling System Cleaner.
Choose 1 of the following options.
Add 0.5 L (1 pint) of cleaner per 15 L (4 US gal) of the cooling system capacity.
For cooling systems with heavy deposits or plugging, add 0.5 L (1 pint) of cleaner per 3.8 to 7.6 L (1 to 2 US gal) of the cooling system capacity.
Install the cooling system filler cap.
Start and run the engine at low idle for a minimum of 30 minutes. For cooling systems with heavy deposits or plugging, run the engine for 90 minutes. The coolant temperature should be at least 82 °C (180 °F).
Improper or incomplete rinsing of the cooling system can result in damage to copper and other metal components.To avoid damage to the cooling system, make sure to completely flush the cooling system with clear water. Continue to flush the system until all signs of the cleaning agent are gone.
Stop the engine and allow the engine to cool. Loosen the cooling system filler cap slowly in order to relieve any pressure. Remove the cooling system filler cap. Open the drain valve (if equipped) or remove the cooling system drain plugs. Allow the water to drain. Flush the cooling system with clean water. If equipped, be sure to flush the heater and any related supply and return lines. Close the drain valve (if equipped). Clean the drain plugs. Install the drain plugs. Refer to the Specifications Manual, SENR3130, "Torque Specifications" for more information on the proper torques. Fill the Cooling System
Fill the cooling system no faster than 19 L (5 US gal) per minute to avoid air locks.
Fill the cooling system. Refer to this Operation and Maintenance Manual, "Fluid Recommendations" for more information on cooling system specifications Refer to this Operation and Maintenance Manual, "Refill Capacities" for information about the