Walker Diesel water/temp light

Discussion in 'Mechanic and Repair' started by tbhaney, Aug 18, 2006.

  1. tbhaney

    tbhaney LawnSite Member
    Posts: 3

    I picked up a used Walker Diesel (Kubota D-600). Supposedly the engine was rebuilt about 10 hours ago. The Water/Temp light is always on. I've only run the machine for a couple of hours so far, but keeping an eye on the temp it slowly climbs to over 200*F, I haven't run it long enough to see if it levels off there or keeps climbing. I've checked the radiator fluid level (Fresh looking antifreeze and is full), made sure the radiator screen is free of debris, no leaks anywhere. The wires coming from the thermostat housing are secure and don't appear to be pinched anywhere. Question about what the normal operating temp for that diesel should be (manuel says the thermostat should start to open at 180* and fully open at 203*) and any ideas to why the Temp/Water light comes on (even before the machine is warmed up).

    Thanks for any help
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Un-plug the wires at the thermostat housing and see if the light goes out, If so the wire circuit is OK (not shorted) and the sending unit is most likely bad.
    Not sure what temp. this should run But 210 to 220 is normal on most gas engines, Over 220 is running on the hot side.
  3. tomo

    tomo LawnSite Senior Member
    Posts: 660

    hello,if electrical is ok
    1/pressure test cooling system 4 leaks[checking visually is only guessing]
    2pressure test rad cap .Caps ability to hold pressure in system raises boiling point of system.
    3/ check coolant antifreeze with guage to determine % of glycol. If i remember correctly walkers run up to 50% mix
    4/place rad thermometer in rad when machine at operating temp [caution opening rad very hot use rag ] read temp
    5/remove thermostat and check operation in a container of gradually boiled water. Unless u operate in cold conditions change thermostat 4 the next lower spec. Hot spec thermostats are primarily used to lower emmisions.
    . There is no margin 4 error when temp runs this close to the borderline of overheating.Most industrial diesels run 180-195 operating.
    6/Walker have had trouble with fans and fan control electrics.There have been numerous changes to this set up over the years to improve fans ability to cool.
    7/ Due to the systems borderline ability to cool system and with 99% of makers appling the just enough principal radiator internal cleanliness is a MAJOR PRIORITY.Machine history unknown ??? remove rad and have it cleaned by a rad repair shop.Moderate cost usally

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