FILM-WARNING 1925007 - Caterpillar

Sealed Pressure Overflow
A sealed pressure overflow assembly prevents loss of coolant through the radiator overflow tube when machine is operating on a slope.Due to expansion of the coolant by rising temperture, a pressure will be built up in the cooling system each time the engine is started. When the system pressure reaches 13 3 PSI above ambient pressure, pressure relief valve (1) opens to relieve the pressure. If the cooling system has been overfilled it allows some coolant to escape through the radiator overflow tube. The valve closes when coolant temperature levels off. It remains closed unless there is a further increase in pressure.When the temperature of the coolant falls, a vacuum will result in the cooling system. When the vacuum reaches 1 PSI less than ambient pressure, vacuum release valve (4) opens and lets air in through the overflow tube. This vacuum release valve also functions when draining the cooling system.
SEALED PRESSURE OVERFLOW
1-Pressure relief valve. 2-Seal. 3-Screen. 4-Vacuum release valve. 5-Opening to overflow tube. 6-Gaskets. 7-Cover.To remove the relief assembly, remove the screws that hold seal (2) in place and remove the housing and seal plate. Inspect gaskets (6).When installing gaskets (6) (one on each side of the seal), make sure the correct hole in the gaskets aligns with opening (5) to the overflow tube.Electrical System
Most of the electrical system testing can be performed on the machine. The machine wiring insulation must be in satisfactory condition, the wire and cable connections both clean and tight and the battery fully charged. It should be remembered an "on-machine" test usually indicates a component must be removed for further testing.Battery
A load test should be made on a battery that discharges very rapidly when in use. To do this apply a resistance of three times the ampere/hour rating of the battery across the battery main terminals. Allow the resistance to discharge the battery for 15 seconds and immediately test the battery voltage. A 6 volt battery in good condition will test 4.5 volts; a 12 volt battery in good condition will test 9 volts and a 24 volt battery will test 18 volts.Starting System
Use a D.C. voltmeter to locate starting system components which do not function.Turn the disconnect switch ON and push the circuit breaker reset button. Turn the HEAT-START switch to the START position. Starting motor solenoid operation is audible as the starter motor pinion engages with the ring gear on the engine flywheel. The solenoid operation should also close the electric circuit to the motor. Attach one voltmeter lead to the solenoid terminal that is connected to the motor. Ground the other lead. Turn the HEAT-START switch to START and observe the voltmeter. A battery voltage reading indicates the malfunction is in the motor. It must be removed for further testing. No voltmeter reading indicates that the solenoid contacts do not close and the solenoid must be repaired or the starter pinion clearance should be adjusted.A starting motor solenoid that will not operate may not be receiving battery current.