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Hitachi UH181 1986 help

BCOG ยท 2022-07-14 18:34

Hi, new user of the site. I have a little collection of older machines growing on my property. The heaviest of which being a 1986 Hitachi UH181. Since moving it up the very steep grade while dragging a 20,000lb rubber track carrier behind it 2 years ago; it has sat under a pole barn. Started it today, it runs no problem. I replaced the inline fuel pump because the old one wasnt wired in with a fuse and blew, and put 2 new batteries in. There seems to be a decent amount of fluid in the hydraulic reservoir (AW32?) Not sure which fluid it takes. The hydraulic controls are baaaarely working if at all, juust got the boom lifting. I pressure washed all the rollers in the tracks as they had dried clay like concrete in them. Cant get it to move now. I am not a mechanic, but I am mechanically inclined. where I lack all knowledge base is about hydraulic systems. Where should i begin? Sorry for the long story! Any info helps! Cheers and thanks for your time

Replies25
  1. #1361brock2022-07-14 19:06

    welcome to HEF, Not being a wise guy but how did you determine the hydraulic level was good. Is there a sight gauge thats all fogged up or did you remove the cover with all the bolts and check.

  2. #2BCOG2022-07-14 19:36

    Thanks for the reply Brock, I just removed the cap and put a clean end of a stick in there and its super low. I thought it was much higher when i looked in from the top. Going to go grab aw32 as i think its the standard fluid then? I think its a 220L tank in there.

  3. #3361brock2022-07-14 20:35

    The boom needs to be down the stick out and the bucket in the full curl position touching the ground. That is the position for the hydraulic level. After you relieve the air pressure in tank by lifting the air relief valve on top of fill cover. Then remove the cap bolts from cover to fill.

  4. #4361brock2022-07-14 20:38

    What cap did you put a stick in? Can you show me?

  5. #5excavator2022-07-15 11:13

    AW32 might be a bit light, I would go with AW46. Either would work but 46 is better for our north west coast climate.

  6. #6BCOG2022-07-17 13:21

    Yeah I ended up pouring 140L of AW46 in as the stick cylinder has a slow leak and Im sure the pump is tired. Got the stick out, bucket curled in and boom down, im just below the viewing gauge still. I think the track chain on the left side may be seized. Im going to give it another pressure wash, sledgr hammer it and spray some move it, wd or honey goo in the chain as best i can

  7. #7BCOG2022-07-17 13:23

    Here, the cap on the right. The left cap has the pressure relief valve, so i just pop the right one open. All functions work great now except the right track i think the track chain is seized

  8. #8361brock2022-07-17 20:56

    The cap you removed to add oil is where the hydraulic filters are?

  9. #9361brock2022-08-05 21:41

    I remove the cap with the air relief valve for adding hyd oil, can see inside tank better. The other caps are where the hyd filters are, can't see level that good.

  10. #10BCOG2022-08-05 22:59

    Ok ill give it a try. I pressure washed the track rail like crazy, sledge hammered it, lubricated it with honey goo. Still absolutely nothing. Completely drags. I removed the cap on my outer final drive, gear oil was perfect. But I was expecting a planetary with a sun gear, so i could remove it and free-wheel the track so its out of my pole barn. But its just one big gear. My friend recommend I try pulling the motor away, as it might be the problem. Any ideas?

  11. #11skyking12022-08-06 00:38

    no way to lift the track off the ground using the boom and stick?

  12. #12BCOG2022-08-06 01:47

    Not yet, thats why I have to get it out of the pole barn. Then i could see if it would turn without weight on it

  13. #13skyking12022-08-06 10:26

    you can lift the one end with the boom? I'd get big cribbing and a jack, and lift the counterweight end up and crib it at the carbody, then press down with the boom and lift the other end. Then you could try free spinning it.

  14. #14361brock2022-08-06 11:14

    Do you feel the engine or hydraulics bogging down like it's trying when you engage the track that won't move?

  15. #15361brock2022-08-06 11:25

    The brakes are released by hydraulic pressure when you engage to move. I have service & repair books for the 143lc, I'll check what that planetary looks like. i've had the pump drives out and the brake discs, but don't recall trying to free wheel it with them out.

  16. #16BCOG2022-08-06 14:22

    Here are some pictures. In between the tracks on the drive side is a massive cover with 3 removable covers and i think a gear oil fill level. When I removed the outer cover its just one big gear and it cant move as the cover has a tooth that holds it in place. It has a UH16 tag on the door

  17. #17BCOG2022-08-06 14:43

    No i cant turn the housing inside the building.

  18. #18skyking12022-08-06 15:07

    You don't need to turn the housing if it's pointed forward jack up the back end and then lift up the front end with the bucket where it's sitting.

  19. #19361brock2022-08-06 15:43

    If you want to access the planetary gears your on the wrong side. You have to drain the gear oil from other side then remove all the capscrews to remove big cover. You won't be able to position the cover in the proper position to use drain plug because you can't move that side. If that compartment is full you have a problem with hyd oil getting past seals of track motor and mixing with gear oil. But after you do remove the big cover you will be able to extract the sun gear or shaft that drives planetary. Then maybe you can propel from other side. I will get my book later to verify.

  20. #20361brock2022-08-06 16:04

    The UH16 japan version of UH181 which was made for European market.

  21. #21Tones2022-08-06 17:41

    You blokes are confusing yourselves. The posted photos aren't a planetary drive but it's a reduction drive similar what dozers had back in the day. Behind the cover mentioned is the hydraulic motor. If that is removed then you should be able to freewheel that track. The machine would probably drive fairly straight with just the the other track driving.

  22. #22361brock2022-08-06 19:55

    Tone is right, I remember that was the norm with early excavators of all the brands including Cat. I just thought being my UH 143 had planetary drive that the whole series also did.

  23. #23Tones2022-08-06 21:09

    The UH181 is an earlier series

  24. #24BCOG2022-08-07 23:53

    Definitely not jacking this up... its over 110,000lbs

  25. #25BCOG2022-08-07 23:56

    Yes sorry it is a UH16. 1986. On my transfer papers its says uh181 hitachi 400