JD. 700H just turning circles

[bubblehead]

Hello everyone. Im new to this forum and need some help. I bought a 2001 J.D. 700H dozer back in Dec. and been using it off and on every other day or so when i first got it. Well with that said I had to work an outage for about 3 weeks straight so the dozer sat. I go to run it yesterday and this is what is happening. The parking brake has to be engaged and the joystick in the neutral position in order for it to start. Soon as I hit the switch it fires up as always but this time the right side track starts turning and the left is not . I start doing a circle . I shut it off and cheched to make sure I was in neutral and it was . Start it again and same thing . I try shifting forwards and backwards and it changed nothing still going in a circle. This is my first time owning a dozer but i have helped work on my uncles before so I kinda can work on them. We have alway had tractors and have done most of our repairs so I can do some of the trouble shooting with some help.

Thanks

[Jim B]

Welcome to the boards.

I will say having a 700H puts you very much on the new side of this group, 16 years newer than my 450E. Hopefully someone familiar with them will chime in with some help on your problem. Have you called your JD dealer and asked if they might have encounter this before? There might be a common issue they have seen with these.

Your machine is hydrostatic drive, has a computer, and at least some electronic controls, doesn't it? Does it show or allow you to bring up fault codes? My first thought is to check electrical connectors. A lose or dirty connector can do funny things. Also look for a pedal, or linkage, not fully moving back or a stuck switch. Do you have the technical manual set for it? TM1858 the operation and test manual should have wiring diagrams and testing/diagnosis info. TM 1859 the repair manual gives the nuts-and-bolts info of making the repairs. Below is a link to the TM1858 manual on the JD Construction and Forestry bookstore. As you can see on the lower part of the cover page preview, along with the TM1859 repair manual there are several component manuals listed as well, some of those may or may not be needed. TM1858 should have the info to get you started on diagnosing the problem. When you open that page, you can check the other manuals by typing the publication number in the center box and hitting the search. The Operator's manual (TM201705) is free to view or download there as well, if you don't have a copy. I took a quick look at the operator's manual, and it looks like there could be some info in section four that might help you.

TM1858

If you don't have it here is a link to the 700H online parts catalog yu can use and print info from.

700H parts Catalog

Sorry, I know this isn't much help. When you find problem, it would be great if you would post the cause and fix so we can start building some info on newer machines. Good luck.
Jim

[bubblehead]

Yes it is hydro. I've talked to the local dealer and they said they would just have to come out and check it out They were not very helpful. Several people suggested changing the filter so I did this afternoon. Started it up and all was ok so I thought. It did not move. The right track was not pulling like before. I shifted it forwards and it went forwards like it should. Then I shifted it in reverse it moved about 30 foot and then it started doing the same thing as before. Right track is pulling and left is not and going in a circle. Seems to be something in the pump. I'm going to change the fluid this weekend and see if that works maybe the fluid is breaking down.

[LeonardL]

Dude I hate to be the bearer of bad news but you really don't have a choice but to have the dealer come out and plug their monitor up to your machine. Unfortunately that is the way of things these days. If I were to make a guess I would say a couple of things might be the culprit. One is rodents getting in and chewing on the wiring and cutting one or more of the wires that connect your controlling system. And two if you have had any storms where lightning got close enough to scramble the brains in the PCU. I've actually seen that happen on more than one occasion. Your "H" is all fly by wire and with Deeres proprietary programming they are the only ones who can fix your machine. And yes they are a bit blasé about it when you go in. It is their meal ticket and yet they act like they don't want to accept the responsibility for what they have created. Sorry dude!! It is what it is at this point.

[bubblehead]

Thought I'd post and let everyone know what we found out. Well its been a long weekend trying to get to the bottom of the issue with my dozer going in circles and i finally did with some help . First we had to figure out if it was electrical or mechanicial. By checking several things we determined it was electrical. There had to be a short in one of the wires or the controller was bad. Didn't think it was the controller so we started looking for a bad connection or a wire somewhere rubbed into and shorted out. Looked everywhere possible and found nothing so we thought maybe it was the controller. Took the cover off to look at the controller and to my surprise when i raised it up there was a nest with two mice sitting in it. I eased it back down and had my wife to get her phone and take a few pics of them so I could post later. When I saw them I started thinking they may have chewed some of the wires into . Well they had . Long story short we fixed what they had chewed up and all is good. I ran it today for a couple of hours without any issue . Tried to load pics but couldn't.

[Jim B]

Thank you for letting us know what you found. Glad to hear it was that simple and inexpensive to repair. Bad connections, loose, broken wires and critter damage are often the first things to check. Mouse damage is not uncommon. It seems at least some companies are using soy products to make the insulation now, just inviting critters to chew on things.

As for posting pictures. You can't post direct to the site from your phone or computer, you have to use a third-party hosting site. This site has a dedicated server for that purpose. You can read about using it on the "Messageboard Q&A and Announcements" Board. You have to contact Lavoy to set au a separate account to use it. Imgur and Postimage are a couple websites that work as hosts as well.

Good luck and I hope that is the last of your problems for a long time.
Jim

[LeonardL]

Rodents cause more issues and damage to heavy equipment than any other source. Even us humans. I figured you either had some sort of rodent chewing on the wires or was lightning stuck. You got lucky dude. Usually they cross things up and it scrambles the PCU. Glad you got it sorted before they did any more damage. I have a devout hate for mice especially and all rodents in general.

A friend of mine lost a really good 931 Cat loader because a pack rat chewed through the positive battery cable and shorted it behind the cut off switch. This caught the machine on fire and it burned to the point of being scrap metal. What was left of the rat was still stuck to the cable after it had burned. I can't count the times I have had to re-wire a machine because of mice, chipmunks, squirrels and pack rats.