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Komatsu Hydraulic Fluid Recommendation?

TD-8 · 2009-05-27 20:45

what type (weight) oil should I use in the hydraulic system of a komatsu mini excavator? some information is showing standard hydraulic oil and some are showing 10w or 30w non-detergent motor oil..... thanks luke:usa

Replies24
  1. #1upnover2009-05-27 23:27

    First check the owners manual if you have one, then a dealer, failing that I would think an ISO 64 or 46 hydraulic oil would suffice. I cant see motor oil being the prefered choice but I could be wrong.

  2. #2TD-82009-05-28 20:11

    I don't have an owners manual, but i will try to get in touch with the komatsu dealership. some of the larger komatsu excavators use a 10w or 30w in the hydraulic system, like the the komatsu dozers do. any one have any experience with what other komatsu mini excavators use? thanks luke:usa:

  3. #3Red Bank2009-05-31 22:19

    I put 5 gallons of 10w in our PC78 last week,per the Komatsu dealer's advice, which is where I bought the fluid. If this helps?

  4. #4Iron Horse2009-06-01 05:29

    In hot climates like Australia , hydraulic oil can get very thin . I have used 15W40 engine oil with great success in the excavators i have owned .

  5. #5tacbob2009-06-01 07:05

    I have just got a PC35mr-2 minni in our workshop and it takes std engine old. so for our conditions it is the same as ioirn horse has said a 15w40 eng oil.

  6. #6thebig450es2009-10-04 19:27

    it it different for a pc50uu-1?

  7. #7Landworks2009-10-05 14:43

    In Arkansas climate, you should be using a 30W oil for hydraulics.

  8. #8thebig450es2009-10-05 14:47

    so just regular engine oil 10w-40w?

  9. #9MrKomatsu2009-10-05 17:53

    :usait depends on the area in which you work and live all komatsu manuals list different ambinat temp..ranges all the oil listed above will work without any problems....:drinkup

  10. #10John C.2009-10-05 21:27

    I've always used AW46 in Komatsu excavators. Engine oil will work but is way too expensive, especially for older machines that might develop big leaks. That's my generic response. On the other hand you should get an operator's manual and use what is recommended for your climate.

  11. #11thebig450es2009-10-05 22:52

    how much is 46 about? Im still trying to locate the manual for it, i can't find the serial # yet on it . so regular engine oil would work. Id like to run the proper fluids

  12. #12John C.2009-10-06 21:58

    AW46 is 10 weight hydraulic fluid. When I was buying lots of it the cost was about half the cost of motor oil. Good luck on finding the manual. You could try calling your local Komatsu dealer.

  13. #13penny coutts2009-11-08 08:51

    Komatsu hydraulic oil We are having similar troubles here in France; almost no-one stocks 10w monograde diesel engine oil. We specially ordered a drum and have had a serious leak and run out. Had to put 46 hydraulic oil in (lost that too as hose keeps blowing - that's another story). No-one can tell us for sure if it will damage anything (if we ever fix the leak!)

  14. #14MrKomatsu2009-11-09 06:44

    you need 10w hydralic oil not engine oil.....aw46 is the all around multi use oil ..komatsu also recommends it....30w engine oil will work in a pinch without damaging componets....why is the leak not fixed yet?:usa:Banghead

  15. #15penny coutts2009-11-09 12:48

    Komatsu hydraulic oil The low pressure (return) pipe between the oil cooler and oil filter keeps blowing off. Previously held on with a jubilee clip now wont stay in place even with a heavier duty clip. We have removed the filter to change it & ordered one, for delivery Thursday (this is France!!!) but tomorrow will take the one off our PC10 and take it over to the job to try it. Any other suggestions why the pressure could be building up - or where a blockage might be?

  16. #16thebig450es2009-11-09 13:57

    Have you flush out the system?

  17. #17penny coutts2009-11-10 17:58

    It flushed itself! But problem now solved - the oil filter was in need of a change and has now been done and the pipe stays on. Thanks to those who offered help.

  18. #18thebig450es2009-11-16 10:59

    I saw in my book, its says SAE 10w-30w

  19. #19PME2012-08-16 14:09

    What Would be the consequences of using a too thin oil type? I'm currently running my pc28 with aw32 oil (in summer) and since i use that, stick cylinder is acting wierd. With the bucket in the air, pulling the stick, it kind of drop freely till vertical, then still holding the command There is a 2 or 3 seconds delay nothing is moving, then it finally complete its movement. Internal packing wear? Oil too thin? Problem with the reliefs? Also, not much power when sticking out... Thanks a lot

  20. #20apm2012-08-18 18:01

    I've got almost the same problem with my PC50uu-1. Strangely enough, in the manual diagnostics section it gives time specs for certain operations. For the "arm in" command the book says maximum allowable delay when arm comes vertical is 3 seconds. Almost makes it sound like it's expected. Greg

  21. #21Mud Logger2015-06-13 16:55

    I was told by our oil supplier that aw32 is a 10 wt for colder temps. Aw 46 for mild weather is 15 wt. aw68 is for warmer up to 90% is 20 wt. There is also aw 120 at a 30 wt.

  22. #22Mud Logger2015-06-13 17:00

    On that arm delay I once read that most hoes hesitate when the stick is at 90 degrees to the boom, to let the operator know that the arc of the bucket will be rising so the boom can be lowered to keep the trench bottom level. Some one else must know more about this feature on this site.

  23. #23Jay432018-06-11 10:45

    do you still have your pc28?

  24. #24obas20702023-12-26 14:41

    You can get them online, but it’s not the actual manual, it’s a file that goes for around $15. Download it and print it out. Komatsu Pc50UU-1 Excavator Service/Repair Manual PDF Download - PDF WorkShop File Komatsu_Pc50uu-1_Shop_Manual_Serial_Number_1001_And_Up.pdf Download Link: https://www.manualboss.com/a/downloads/-/8741587b34efb374/a04cf503ac0e6337