4-32 SHB 803 en – Edition 2.4 * 803s410.fm
Engine
4.29 Oil pressure switch
☞Remove the cable connection from the oil pressure switch (in the area of the cutoff
solenoid).
☞Start the engine, check for correct idling speed.
☞Measure the resistance of the oil pressure switch as shown by means of an ohmmeter.
➥Oil pressure switch is OK: infinite resistance.
➥The oil pressure switch is malfunctioning if the oil can pass.
• The oil pressure can also be measured with a mechanical dial gage.
☞Remove oil pressure switch A and replace it with the dial gage.
☞Start the diesel engine and measure the oil pressure.
➥Replace the oil pressure switch if malfunctioning or determine the cause for insuffi-
cient oil pressure.
4.30 Checking the coolant circuit
Leakage check
☞Fill up the radiator correctly.
☞Install test appliance on the radiator as shown.
☞Increase the pressure in the cooling system by means of a hand pump to about 0.75 –
1.05 bar (10.8 – 14.8 psi).
➥If the pressure drops at the pressure gage, check the lines and the connections for
leaks and repair them.
Checking the radiator cap
☞Remove the radiator cap and install it on the test appliance as shown.
☞Increase the pressure by means of a hand pump to about 0.75 – 1.05 bar (10.8 – 14.8 psi).
➥The radiator cap must open within this pressure range.
4.31 Cleaning the cooling water channels
☞Let the engine and the cooling system cool down.
☞Remove the radiator screw plug.
☞Drain the coolant – see chapter Draining coolant on page 3-25
☞Rinse the cooling circuit.
☞Add coolant – see chapter Checking the coolant level/adding coolant on page 3-23.
Measurement prods
Fig. 51: Oil pressure switch
Fig. 52: Position of oil pressure switch
A
Fig. 53: Checking the radiator for leaks
Radiator cap
Fig. 54: Checking the radiator cap
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