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D30D Water Truck Hyd oil tank is so hot cant keep hand on it

still learn'n · 2014-08-14 21:48

We have A Cat D30D water truck that I just put a brand new water pump on the tank yesterday and run it today and the hydraulic tank was so hot after running 30 min that couldn't hardly hold my hand on it! Where would be the first place to look? No I haven't changed filters lately will have to do that but it almost sounded to me like when I run it that the pump had was sucking a little air or something queer! Got any suggestions? Serial # is 3AJ00294 Thanks Jerry

Replies13
  1. #1clintm2014-08-14 22:32

    you didn't leave a rag or something in a line did you does it sound like it's may be going over relief that would cause heat real quick

  2. #2still learn'n2014-08-14 23:40

    Well if I did I sure didnt try to it pry would have been paper not cloth so would that plug it up? Thanks Jerry

  3. #3Deeretracks2014-08-14 23:44

    Oh yeah, a paper towel can wreak havoc on a hyd circuit.

  4. #4still learn'n2014-08-14 23:54

    So how do you go about troubleshooting it? Will there be pieces in filter? Would an infrared tell gun tell anything?

  5. #5Shimmy12014-08-14 23:58

    This probably dumb question but what happened to the old pump?

  6. #6still learn'n2014-08-15 00:03

    I had rebuilt it once and the side plate of the water pump had corroded enough that I wasn't sure how long the seal was going to stay and it started leaking water out there and it wasn't much more to get new pump as to get the pieces!

  7. #7Shimmy12014-08-15 00:05

    This probably dumb question but what happened to the old pump?

  8. #8Shimmy12014-08-15 00:08

    So same drive motor as before. Did you make sure the pump spun freely before reinstalling drive motor?

  9. #9still learn'n2014-08-15 00:10

    Same drive motor I turned it by hand when I was aligning the splines!

  10. #10Shimmy12014-08-15 00:19

    Does the motor have a case drain? An if so is there a filter in the case drain line back to tank? Generally hot hydraulics are caused by bad cooling, restriction, or too much internal leakage.

  11. #11still learn'n2014-08-15 00:21

    The motor doesn't have a case drain just inlet and outlet! I wondered if hyd motor was getting weak!

  12. #12Shimmy12014-08-15 00:30

    A infrared should tell the story. Shoot the outlet on pump after running for 10 min or so while the pump is running. Also what else is ran off this hydraulic system? Does it have a cooler? If it does shoot the inlet and outlets of cooler. If pretty much same temp then cooler plugged. If outlet oil is more than 50° cooler chances are the flow is too slow. Could be caused by plugged filter or stuck cooler bypass. Oil coming out of cooler should be 15-30° cooler

  13. #13Shimmy12014-08-15 00:33

    Outlet on drive motor I meant.