Cooling system - Td5 (Outlet housing): Description and operation

Outlet housing

A cast aluminium outlet housing is attached to the cylinder head with three bolts and sealed with a gasket. Coolant leaves the engine through the outlet housing and is directed through a hose to the heater matrix, the radiator or the by-pass circuit.

An Engine Coolant Temperature (ECT) sensor is installed in a threaded port on the side of the outlet housing. The sensor monitors coolant temperature emerging from the engine and sends signals to the Engine Control Module (ECM) for engine management and temperature gauge operation. ENGINE MANAGEMENT SYSTEM - Td5, DESCRIPTION AND OPERATION, Description.

Expansion tank

The expansion tank is located in the engine compartment. The tank is made from moulded plastic and attached to brackets on the right hand inner wing. A maximum coolant when cold level is moulded onto the tank.

Excess coolant created by heat expansion is returned to the expansion tank from the radiator bleed pipe at the top of the radiator. An outlet pipe is connected into the coolant pump feed hose and replaces the coolant displaced by heat expansion into the system when the engine is cool.

The expansion tank is fitted with a sealed pressure cap. The cap contains a pressure relief valve which opens to allow excessive pressure and coolant to vent through the overflow pipe. The relief valve is open at a pressure of 1.4 bar (20 2

lbf.in ) and above.

Heater matrix

The heater matrix is fitted in the heater assembly inside the passenger compartment. Two pipes pass through the bulkhead into the engine compartment and provide coolant flow to and from the matrix. The pipes from the bulkhead are connected to the matrix, sealed with 'O' rings and clamped with circular rings.

The matrix is constructed from aluminium with two end tanks interconnected with tubes. Aluminium fins are located between the tubes and conduct heat from the hot coolant flowing through the tubes. Air from the heater assembly is warmed as it passes through the matrix fins. The warm air is then distributed in to the passenger compartment as required. HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.

When the engine is running, coolant from the engine is constantly circulated through the heater matrix.

Radiator

The 44 row radiator is located at the front of the vehicle in the engine compartment. The cross flow type radiator is manufactured from aluminium with moulded plastic end tanks interconnected with tubes. The bottom four rows are separate from the upper radiator and form the lower radiator for the fuel cooler. Aluminium fins are located between the tubes and conduct heat from the hot coolant flowing through the tubes, reducing the coolant temperature as it flows through the radiator. Air intake from the front of the vehicle when moving carries the heat away from the fins. When the vehicle is stationary, the viscous fan draws air through the radiator fins to prevent the engine from overheating.

Two connections at the top of the radiator provide for the attachment of the top hose from the outlet housing and bleed pipe to the expansion tank. Three connections at the bottom of the radiator allow for the attachment of the bottom hose to the thermostat housing and the return hose from the oil cooler and the feed hose to the fuel cooler.

The bottom four rows of the lower radiator are dedicated to the fuel cooler. The upper of the two connections at the bottom of the radiator receives coolant from the oil cooler. This is fed through the four rows of the lower radiator in a dual pass and emerges at the lower connection. The dual pass lowers the coolant temperature by up to 24°C before being passed to the fuel cooler.

Two smaller radiators are located in front of the cooling radiator. The upper radiator is the intercooler for the air intake system and the lower radiator provides cooling of the gearbox oil. EMISSION CONTROL - Td5, DESCRIPTION AND OPERATION, Emission Control Systems. MANUAL GEARBOX - R380, DESCRIPTION AND OPERATION, Description. AUTOMATIC GEARBOX - ZF4HP22 - 24, DESCRIPTION AND OPERATION, Description.