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Hydraulic pump leaking

Travis Bales · 2020-10-01 19:05

Member HI first time posting ...I have a caterpillar 955l #85j10332 that I believe is leaking around the hydraulic pump. I purchased the seal from cat but my question is do I need to drain the hydraulic tank before removing the pump ?thanks for any advice im pretty new at this .travis .

Replies22
  1. #1Vetech632020-10-01 19:40

    If the bottom of your hydraulic tank is above the pump mount it will drain the entire tank. Better safe than sorry.

  2. #2Travis Bales2020-10-01 20:59

    Ok thanks

  3. #3DB22020-10-01 21:09

    You could always apply a vacuum to the tank while you cap off the line. A shop vac is your friend here. Maybe your oil needs changed anyway though.

  4. #4Dave Neubert2020-10-02 08:02

    Yes you need to drain the tank

  5. #5Travis Bales2020-10-02 09:09

    I'm assuming there is a drain plug under the tank ? Is there any special process for refilling the system ? Do I need to bleed the system or anything ? I've ordered a service manual it just hasn't made it here yet ..

  6. #6Tones2020-10-02 15:28

    Ensure the pump is full of oil before you start the engine. If it has a casedrain then fill through there.

  7. #7Dave Neubert2020-10-02 19:22

    The pump is a vane pump no case drain just fill tank it will fill pump if you want to be sure loosen the 4 bolts on the suction line until oil comes out

  8. #8Travis Bales2020-10-02 20:02

    Ok thanks I will check to see it does..what if it doesn't have a case drain then how do I get the oil in the pump ?

  9. #9Travis Bales2020-10-02 20:02

    Ok thanks ..

  10. #10Travis Bales2020-10-02 21:42

    Any idea on what would cause this to be leaking oil? This picture is taken from the right side under the hydraulic tank

  11. #11Vetech632020-10-03 05:28

    That looks like a oring inside that hole bore. That is where a tube goes into and the oring seals around the perimeter of the tube. Something is missing.

  12. #12Nige2020-10-03 06:29

    I don’t see any method of fixing a hose or tube to it. Is it not a core plug like the one above and to the left of the white circle that is not leaking..?

  13. #13Dave Neubert2020-10-03 08:06

    CAN'T TELL WHAT THAT IS BUT IT DON'T LOOK LIKE THE HYD PUMP

  14. #14Dave Neubert2020-10-03 08:21

    First picture is the pump looks to be leaking from the mounting O ring there is also a small weep hole in that area if it is coming from there you will need to replace the shaft seals

  15. #15Travis Bales2020-10-03 14:10

    Yeah I've got the housing o ring just haven't tore into it yet ..I need to drain the hydraulic tank first. Is this the drain plug fir the hydraulic tank?

  16. #16Travis Bales2020-10-03 14:20

    .I just went out and took a few more pictures and it seems to be leaking out of the round plug hole .

  17. #17Travis Bales2020-10-03 14:25

    Any ideas what this could be ?

  18. #18Nige2020-10-03 15:11

    I’ll repeat what I said before. It looks like a core plug, especially when the photo is blown up a little. EDIT: It's on the steeering clutch cover. See below. I'm even more convinced it's a core plug because there are various ones listed on the parts breakdown. It's not clear what Part Number it is though. What diameter is the hole.?

  19. #19Travis Bales2020-10-03 15:28
  20. #20Nige2020-10-03 16:12

    Here's a youtube video. The only difference is that this is on an engine so it will have coolant behind it rather than oil which your plug has. I would suspect that the biggest difficulty you will face is to determine the size of the leaking plug in your machine and get hold of a correct replacement.

  21. #21Dave Neubert2020-10-03 17:46

    I agree with Nige just measure it and drive one in look on the other side see if it has a plug

  22. #22Travis Bales2020-10-03 20:06

    Thanks so much ..I'll give it a shot ..