FUSO 4M4 – COOLING – PRESSURE CAP, THERMOSTAT

Inspection procedure

Inspection: Pressure cap
(1) Pressure cap valve opening pressure
• Replace the pressure cap if the measured value deviates from the standard value range.

(2) Inspection of vent valve
• Before starting the inspection, check the level of coolant in the reservoir tank.
• Run the engine at full speed. Stop the engine when the level of coolant in the reservoir tank noticeably rises.
• Wait until the coolant temperature drop to the ambient temperature. Then, check if the coolant in the reservoir tank has returned to the same level as that confirmed before the engine was started.
• If the coolant has failed to return to its original level, the vent valve is defective. In this case, replace the pressure cap.

Inspection: Thermostat
• Stir the water using a stirring rod to maintain an even water temperature in the container, then conduct the tests indicated below.
• If the measured values deviate from the standard value ranges, replace the thermostat.
(1) Valve opening temperature
• Hold the thermostat with wire to keep it away from the heat source.
• Heat the water gradually to the valve opening temperature.
• Maintain this temperature for five minutes and make sure that the valve is completely open.
• Make sure that the valve closes completely when the water temperature drops below 65°C.
(2) Valve lift/temperature
• Heat the water to 95°C with the valve completely open. Maintain this temperature in this state for five minutes and measure the valve lift.

Installation procedure

Installation: Thermostat
• Install the thermostat while aligning the rightmost jiggle valve with the bolt hole in the thermostat case as shown in the illustration.

 

 

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