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2001 JD 750C LGP problems. Please HELP!

powerplusdude ยท 2017-08-12 00:09

Hello all! I am new to the forum and relatively new to owning a 2001 JD 750C LGP dozer with around 12,780 hrs. 1st problem: Started two days ago. Dozer works like a champ for first 30 minutes of day and then goes into "Slow Mo" mode after warming up. Blade hydraulics (6 way) do not slow down though. It is losing RPMs and engine sounds like it's under a load but it isn't. The first time it done it, it would barely pull itself back to the place where I was parking it for the night. Second time it done it, well, it's still out in the field. The dozer got so bad, it would not move at all and then the engine shut off. The engine will turn over but not crank up. I didn't try to crank that long as usually will crank right up just by bumping the switch. I am thinking that the fuel filters might be stopped up or it might be the fuel pump. I already got some new fuel filters to change out the next time I go to the dozer (1 hr away) and was wondering if there was anything else I could try or check to see if it could be something else. Any help or ideas would be greatly appreciated. 2nd problem: This started about 2 days ago also. Mainly when I am backing up, I can hear and feel a grinding in the right side track. It sounds like it is coming from the final drive sprocket. I have yet to check the oil level in the inner and outer final drive due to the dozer and my tools being an hour away from each other. I did, however, check final drive oil level around 50 hrs previous and it was fine. Do ya'll have any other ideas on what could be causing the grinding? Any help or ideas would be greatly appreciated. I don't think the two issues are related but you never know. Oh, and yes, it does have diesel in it. Thanks, Mike

Replies10
  1. #1thepumpguysc2017-08-12 06:12

    Mike, just start w/ the basics, fuel filters & leave the tank cap loose & test her out.. IF you can bring an air tank w/ you, it wouldn't be a bad idea to blow back thru the fuel inlet & return lines going back to the fuel tank.. When your workin it & it starts to slow down, put it in neutral w/ no hydros working, & try to rev the engine back up.. IF it does rev, you have something mechanical or hydro. dragging it down.. IF it wont rev back up, you need to dig deeper in the fuel system.. But it sounds like your on the right path w/ the filter change 1st.. Good luck & keep us posted.. TPG

  2. #2powerplusdude2017-08-12 23:25

    When I was going from forward to reverse and back, the dozer went initially faster going into each direction and did rev up to normal, but after about a second or two it would return to the same loaded, sluggish pace. (So that would tell me the hydros are good?) It did this until finally it would not go in any direction and just set there "under a load" until it shut off. I will look into in on Monday which is the next chance I will get to go by there. Thanks for the reply, I do have access to an air tank. I will give that a try if changing the filters doesn't clear it up. Mike

  3. #3Delmer2017-08-13 09:27

    When a diesel is starving, they will sputter and surge. That kind of sounds like what yours was doing. There's probably a screen in the tank or on the fuel shut off valve on the tank in a JD. Look it up on JDparts . com so you know where to look and what you need before you go back out there. Might have to drain the tank to take the shut off valve out. You do drain the water and dirt out of your fuel tank drain every week right?

  4. #4powerplusdude2017-08-13 23:25

    Thanks for the info Delmer. There is a screen between the tank and the Shut off valve. No, I haven't been draining the water and dirt out of the fuel tank as I don't run the dozer everyday. It makes perfect sense to do that. I don't know why I haven't thought of it, but will start. My plans for tomorrow are: Drain tank (around 15 to 20 gals), clean screen, put some clean fuel in tank, change fuel filters and hope and pray that that was the problem. On a side note, the local JD dealer sold me (2) RE62419 fuel filters. They said the RE62424 fuel filter subbed out to the RE62419. This dealer usually deals with the AG side of JD rather than the Construction side. Is this right, or do I need to find an actual RE62424 filter? Mike

  5. #5CavinJim2017-08-14 00:20

    The JD Ag dealers can get the JD Heavy equip parts--but only if you know the part numbers. Been there, done that--go to jdparts.deere.com and find what you need (you will need all of the serial numbers--equipment and engine). I can't count how many times I've gone to the local Ag dealer with a part number from my 1960s JD 350 crawler and they'll have it in stock--but they can't look it up in their system since it's not Ag! And don't assume JD parts are more expensive--hydraulic hoses by the P/N from our local JD dealer are about 1/4 the price of hoses made up by the local "cheap" auto parts supplier! Shop around and due diligence, but become an expert at the online parts site. My experience is that the JD guys are very happy if you know more about what you need than they do!

  6. #6Delmer2017-08-14 02:36

    It's fine to put the old diesel right back in the tank, assuming you know it's new within the last couple months. Let it settle and siphon it back in leaving the last few inches in the bucket. I would take there word on the filters. Possibly a finer micron rating? Looks like they both have a water drain also. Not that you have to check the drain every week if you never get any dirt or water, just check it often enough to know how often you need to.

  7. #7Coy Lancaster2017-08-27 18:38

    You may also want to add an anti algee fuel additive just in case

  8. #8powerplusdude2019-01-15 21:47

    Not to revive an old post, but I forgot to let yall know what the culprit of the problems I was having was. A $3.50 fuel filter o-ring. Good to know it was something simple but I was about to pull my hair out too. Thanks guys

  9. #9mg23612019-01-16 04:56

    Depends on which engine you have for the fuel filters. Deere used a 6076, 6081 or a 6068 engine. Which engine do you have? Did you supply them with the RE62424 number? That is still a good number.

  10. #10powerplusdude2019-01-16 09:21

    Yea, I went to another dealer and got the RE62424. Thanks