146401-0220 ZEXEL 9 461 611 744 BOSCH HYDRAULIC HEAD 9461611744 1464010220 8943202710

External LeaksPressurize the cooling system using the 9S8140 Cooling System Pressurizing Pump Group and check the following:1. Leaks In Hoses Or Connections Check all hoses and connections for visual signs of leakage. If no leaks are found, look for damage to hoses or loose hose clamps. Also, check for leaks in accessories such as fuel heaters and transmission oil coolers.2. Leaks In The Radiator3. Leaks In The Heater4. Leaks In The Water Pump Check the water pump for leaks before starting the engine, then start the engine and look for leaks. If there are leaks at the water pump, repair the pump or install a new pump.5. Cylinder Head Gasket Leaks Look for leaks along the surface of the cylinder head gasket. If leaks are found, remove the cylinder head and install a new head gasket. Coolant Leaks At The Overflow Tube6. Defective Pressure Cap Or Relief Valve Check the sealing surfaces of the pressure cap and the radiator to be sure the cap is sealing correctly. Check the opening pressure and sealing ability of the pressure cap or relief valve with the 9S8140 Cooling System Pressurizing Pump Group.7. Engine Runs Too Hot If coolant temperature is too high, pressure will be high enough to move the cap off of the sealing surface in the radiator and cause coolant loss through the overflow tube. If this occurs, refer to the portion, Overheating, of the topic, Abnormal Cooling System.8. Air/Combustion Gas In The Cooling System Air/Combustion Gas in the cooling system reduces the heat transfer from hot engine parts to the coolant and causes low coolant flow. The most common causes of air are: * Improper filling of the cooling system trapping air in the system.* Combustion gas leaking into the system. If air/combustion gas is present in the cooling system, the engine should be checked for internal cracks (cylinder head, injector sleeve, cylinder liner) or for a defective cylinder head gasket.The cooling system can be checked for air using the BOTTLE TEST. The equipment needed to do this test is a one pint bottle, a bucket of water, and a hose which will fit the end of the overflow pipe of the radiator. Before testing, be sure the cooling system is filled correctly. Use a wire to hold the relief valve in the radiator cap open. Put the hose over the end of the overflow pipe. Start the engine and operate it at high idle rpm for a minimum of five minutes after the engine is at normal operating temperature. After five or more minutes at operating temperature, place the loose end of the hose in the bottle filled with water. If the water gets out of the bottle in less than forty seconds, there is too much exhaust gas leakage into the cooling system. Find the cause of the air or gas getting into the cooling system and correct as necessary. Internal LeakageIf coolant is found in the engine oil check the following internal components