GILLIG LOW FLOOR, Руководство по обслуживанию

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Engine
85
Cooling System Maintenance
A pressurized cooling system is used on the coach and normally operates at temperatures higher than
non-pressurized systems. It is important that the system is kept clean and leak free, the filler cap and
pressure relief mechanism are correctly installed, and coolant levels are properly maintained.
1. At the surge tank, check the coolant level by observing the level in the sight glass. If liquid is
visible in the sight glass, the system contains enough coolant. If coolant is not visible in the sight
glass, add as necessary to bring the level up to the bottom of the filler cap opening.
2. Check hose connections and tighten clamps as necessary. Hose clamps used on silicone hoses
in the cooling system may require tightening at several intervals after initial tightening. This is
a normal compression characteristic of new or replacement silicone hoses. Check and retighten
clamps until subsequent checks establish that there is no need for further tightening. Replace
cracked, swollen, or deteriorated hoses as necessary. With constant tension clamps, the only
check needed is to make sure the clamp is in place.
3. Check the radiator core and both the driver and passenger heater cores for leaks and for accumu-
lation of dirt obstructing the air flow. Clean the cores with an air hose using low air pressure. It
may be necessary to use a suitable cleaning solution, such as oleum and water, to remove heavy
dirt accumulations from the radiator and core. Inspect and repair bent radiator fins. Repair all
cooling system leaks as soon as they are detected. Refer to the engine manufacturer’s service
manual for procedures for replacing leaking cylinder head gaskets and for the removal and over-
haul of the engine water pump.
4. Inspect the radiator mountings and tighten the mounting bolts as necessary.
5. Check fan operation.
6. Inspect for proper clearance between the fan and the radiator core and fan shroud and correct as
required. The fan shroud must fit airtight against the radiator to prevent recirculation of the hot
air drawn through the radiator.
7. Inspect the baffles between the radiator assembly and the access door. The baffles should be in
good condition and not allow air to recirculate around the radiator.
8. If the engine operating temperature is outside the normal range of 180°–206° F, several possible
causes, starting with the cooling fan, should be checked and eliminated before the thermostat is
removed. A defective thermostat which remains closed, or only partially open, will restrict the
flow of coolant and cause the engine to overheat. A thermostat which is stuck in the full open
position may not permit the engine to reach its normal operating temperature.
Perform regular maintenance on the cooling system according to the specifications in the Preventive
Maintenance chapter of this manual. Hoses should be checked regularly for signs of damage or deterio-
ration and hose clamps should be checked regularly and tightened if necessary.