CLEANING/REVERSE FLUSHING
| CAUTION | The cooling system normally operates at 97-110 kPa (14-16 psi) pressure. Exceeding this pressure may damage the radiator or hoses. |
Reverse flushing of the cooling system is the forcing of water through the cooling system. This is done using air pressure in the opposite direction of normal coolant flow. It is usually only necessary with very dirty systems with evidence of partial plugging.
REVERSE FLUSHING RADIATOR
Disconnect the radiator hoses from the radiator fittings. Attach a section of radiator hose to the radiator bottom outlet fitting and insert the flushing gun. Connect a water supply hose and air supply hose to the flushing gun.
| CAUTION | The cooling system normally operates at 97-110 kPa (14 -16 psi) pressure. Exceeding this pressure may damage the radiator or hoses. |
Allow the radiator to fill with water. When radiator is filled, apply air in short blasts allowing radiator to refill between blasts. Continue this reverse flushing until clean water flows out through rear of radiator cooling tube passages. For more information, refer to operating instructions supplied with flushing equipment. Have radiator cleaned more extensively by a radiator repair shop.
REVERSE FLUSHING ENGINE
Drain the cooling system. See STANDARD PROCEDURE . Remove the thermostat housing and thermostat. Install the thermostat housing. Disconnect the radiator upper hose from the radiator and attach the flushing gun to the hose. Disconnect the radiator lower hose from the water pump. Attach a lead away hose to the water pump inlet fitting.
| CAUTION | Be sure that the heater control valve is closed (heat off). This is done to prevent coolant flow with scale and other deposits from entering the heater core. |
Connect the water supply hose and air supply hose to the flushing gun. Allow the engine to fill with water. When the engine is filled, apply air in short blasts, allowing the system to fill between air blasts. Continue until clean water flows through the lead away hose. For more information, refer to operating instructions supplied with flushing equipment.
Remove the lead away hose, flushing gun, water supply hose and air supply hose. Remove the thermostat housing. See REMOVAL . Install the thermostat and housing with a replacement gasket. See INSTALLATION . Connect the radiator hoses. Refill the cooling system with the correct antifreeze/water mixture. See STANDARD PROCEDURE .
Scheme 28
| 1 - CYLINDER BLOCK DRAIN PLUG |
|---|
| 2 - EXHAUST MANIFOLD AND HEAT SHIELD |
| WARNING | Do not remove the cylinder block drain plugs (1) or loosen the radiator draincock with system hot and under pressure. Serious burns from coolant can occur. |
- DO NOT remove radiator cap first. With engine cold, raise vehicle on a hoist and locate radiator draincock. NOTE: Radiator draincock is located on the left/lower side of radiator facing to rear of vehicle.
- Attach one end of a hose to the draincock. Put the other end into a clean container. Open draincock and drain coolant from radiator. This will empty the coolant reserve/overflow tank. The coolant does not have to be removed from the tank unless the system is being refilled with a fresh mixture. When tank is empty, remove radiator cap and continue draining cooling system.