DRAINING COOLING SYSTEM
| WARNING | DO NOT REMOVE THE CYLINDER BLOCK DRAIN PLUGS 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.
- 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.
Scheme 50
- Tighten the radiator draincock and the cylinder block drain plug(s) (if removed).
- Fill system using a 50/50 mixture of ethylene-glycol antifreeze and low mineral content water. Fill pressure bottle to service line and install cap.
- With heater control unit in the HEAT position, operate engine with pressure bottle cap in place.
- Add coolant to pressure bottle as necessary. Only add coolant to the pressure bottle when the engine is cold. Coolant level in a warm engine will be higher due to thermal expansion.
COOLING SYSTEM - 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
| CAUTION | The cooling system normally operates at 97-110 kPa (14-16 psi) pressure. Exceeding this pressure may damage the radiator or hoses. |
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.
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 DRAINING COOLING SYSTEM . 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 ENGINE COOLANT THERMOSTAT . Install the thermostat and housing with a replacement gasket. See ENGINE COOLANT THERMOSTAT . Connect the radiator hoses. Refill the cooling system with the correct antifreeze/water mixture. See REFILLING COOLING SYSTEM .
