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Recent content by pfpm

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    Hitachi 75zxUR oil leaking from between pumps.

    Best is to pull the tank out, grind around the whole pipe and weld it up. The crack will be a lot bigger once you grind it back. You could try something like araldite but it won't last. Looks like someone has done some welding on it before.
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    Hitachi 75zxUR oil leaking from between pumps.

    Which shaft seal are you talking about? the one on the piston pump is up against the engine which if it was leaking would show up near the flywheel. Not sure whether the small gear pump has a shaft seal but either way if it does and it is leaking it would just leak into the piston pump case with...
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    D9R diff steer problem.

    Thanks Guys. Have put a tech enquirery into Cat to see what comes back. nothing yet.
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    D9R diff steer problem.

    A couple of years ago I overhauled the pump and motor on the steering on a D9R serial no 7tl. all went fine for about 2000hrs and the pump broke up by spliting the spline out of the cylinder block. Rebuilt the pump again bench test fine. When setting it up on the dozer the pump pressure...
    • pfpm
    • Thread
    • Replies: 7
    • Forum: Dozers
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    Hitachi EX 300-3 Hydraulic problem

    When cold some pumps get valve plate to slider separation which is why your track stops completely. Some only do it when hot. The vibration you can feel when hot is the same thing only at a higher frequency. When these machines first started showing these symptoms Hitachi would replace the...
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    Hyd problum with rear boom

    Can you move the spool when the engine is turned off?? If not have you over tightened the through bolts?
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    Hitachi 200-3 pump goes to full stroke

    You can put a multi meter on the output from the PVC and compare the resistance with the good output to see what you get. Should have no resistance when switched. Maybe you have a cold solder inside the PVC?? which is causing a bad earth. regards Mike
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    Hitachi 200-3 pump goes to full stroke

    The two wires going to the pvc are separate earths for each solenoid. Are you saying that when you earth one of these wires (111/103) at the pvc the solenoid destrokes the pump? The pcv switches to earth the coil. Sorry forgot, If the DR is saying that the solenoid is energized I think that it...
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    Hitachi 200-3 pump goes to full stroke

    The wire numbers are from the solenoid to the pvc, They are from a dash 2 model so i hope the dash3 is the same number you may have to check. Yes you have 24v coming from the pump control relay all the time. The solenoid is in series between the pump control relay and the 111,103 wires in the...
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    Hitachi 200-3 pump goes to full stroke

    Try running a separate 24v wire to the solenoid and separate ground. They are 24v coils so I doubt that 12v would be enough to power it. Yes 22v should work but you say you loose the voltage when you plug it into the solenoid. If the pump destrokes ok with a separate power supply you can look...
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    Hitachi 200-3 pump goes to full stroke

    Just to clarify a few things. The solenoids should have 24+ volts to each one all the time, When they switch they are earthed out in the computer. Now when the pump is at full stroke does the DR say that the destroke solenoid is active? When you say that you can destroke the pump using a...
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    ex100.2 bucket cylinder weak & slooooooowwww

    Be very careful with these valves. The solenoid does not do anything under single operation of a function. Not sure the exact sequence but it is something like when you move two spools the lower pressure one will close off a bit and also when you change dig functions it sends a different...
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    ex100.2 bucket cylinder weak & slooooooowwww

    Don't know about the ex 100 but on 120 to 220 ther are proportional valves on some spools. Thier function is to restrict the flow on one circuit so that other functions will work. If one was closed it would only allow a small amount of oil through. From memory they are either in front or behind...
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    Hitachi EX200-3 pump noise

    You can verify that the solenoids are causing the noise by disconnecting the wires. The pump will slowly come on stroke and load up the motor. I would still swap the solenoids around and see what happens( but not the wires) If you want some peace of mind you can pull the pump head off and have...
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    Hitachi EX200-3 pump noise

    The diagnose bit is easy, The clicking noise is the high speed solenoids on top of the pump firing. They become prevalent especially at idle when they fire to keep the pump at minimum stroke, you probably find that as the machine warms up they do it more often. I think that as the pump wears the...
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