For background, I recently (several weeks ago) purchased a JD35ZTS excavator with ~ 6,000 hrs on the clock, from a semi-local contractor who has had it for a while. He said it never gave him any trouble. It is an older machine, but has been reasonably cared for, and he had it serviced 8 months ago. We have a small farm, and I have been looking for small excavator for quite a while just to do odd jobs. If I put 10-20 hrs a year on it, I will be amazed. So the hours on the machine didn't worry me that much. I got it for a good price <$9K, so it seemed to fit the bill for what I need, and is a lot less than the $20-30K for a newer used machine. OK. It came off the trailer fine. The Isuzu engine starts and runs great. Everything was functional, and I used it for a few small jobs just to get familiar with it, moving a pile of gravel and lifting some heavy stuff to move around. I'm pretty good with taking care of machinery, and went through the service manual and am starting to understand these mini-excavators, which are new to me. Tonight, I started it up to dig up a small 4' rock that has been in the orchard forever causing mischief with the mower. The hydraulic movements were erratic. On the left joystick, when I tried to raise the arm, it would work for a second, then quit with no hydraulics. Other functions worked ok. If I rotate the body with the left stick a little, the other functions come back, and I could lower the arm. But it would stop, with no power, but then start again. It seems like this pattern just moved around the machine, with some function or other suddenly stop working, but if I moved a joystick to a different position, function would be restored for a bit, until it stopped again. It is not just one single function, but kind of moving around the machine to different functions, but by moving something else, things would come back. I checked the hydraulic oil in the tank and it is 2/3 full, and had pressure when I released the cap slowly after cooling. When he delivered the machine, I worked it for about an hour, and everything seemed fine. The only thing I noticed was it tends to steer a little to the left over long transport, say down a 100' driveway. I figure one motor must be a little weaker than the other, but nothing I couldn't live with. Other than that, everything functioned just fine, and I could dig a full bucket of dirt with no problem. Did I get snookered on this thing? I didn't expect a perfect machine, but it does have to be functional to be of any use. As it warmed up, it seemed to get a little better, but it was still jerky hydraulically. I parked it in the shed and am wondering where to start looking. I don't know a whole lot about these complex beasts, but I have a feeling I am about to learn. Anything obvious come to mind, other than low hydraulic oil, which doesn't seem to be the case? Thanks for any help any of you more experienced guys can give me.
Good day JD If you could post the hydraulic schematic we may be able to help. Kind regards Uffex
Welcome to HEF JD35 ! It is probably not your issue but check the pilot enable switch in your left arm rest to make sure it is not intermittently breaking contact.
Thanks for the fast replies. Uffex, I'll try to figure out a way to copy the hydraulics. From what I've heard, the early JD35 is essentially a Hitachi machine. mg2361 - I think you lit a lightbulb in my head. When delivered, he had a bungee cord attached to the safety switch arm on the left. I didn't think too much of it, and didn't use it. However, I wonder if he used it to overcome a dodgy switch? The only thing is, when it acted up, one function, such as the boom raise, would not work, but the rotate would (it is set on "backhoe" right now for the controls, so the raise and rotate are both on the left - which I hate and intend to change the setting to ISO). The right hand control would continue to work. It seems like a switch would stop all functions, but maybe not. How sensitive are these machines to hydraulic fluid height in the tank? The manual shows a sight glass, which I haven't found yet, saying the fluid must be within what appears to be a fairly narrow range. I used a clean stick to check the level, and it is about 2/3 full, which I assume is reasonable (plus I haven't found any leaks during storage or use), but it seems low hydraulic fluid could be one explanation for the machine to go from working fine to being jerky and erratic. I'll pull the one panel and try to find the sight window and make sure the fluid is within the lines - but if not, I would think just adding a gallon or two, without overfilling it too much, wouldn't hurt - or is that incorrect? I planned on putting the machine in the shop and going over it top to bottom, doing a full maintenance, changing all fluids and becoming familiar with it, like I do with any new (used) machine. Except for the initial test runs, I haven't used it until yesterday, when I just started it to do the once small job. It's just a little disconcerting that it went from functional to a piece of junk by sitting for a week. I'm a little concerned I bought a piece of junk someone patched up just enough to get it off the trailer. Hopefully not, and hopefully there is something obvious causing this, like the hydraulic fluid being just a little low, or the safety switch acting up. If it's something major, like the control valve, I think I will be giving the contractor a gentlemanly call (to arrange an old fashioned duel perhaps).
Here's some photos from fall 2019. It looks like the 50 series are still Hitachi machines.
Find your sight glass, and put the arm all the way out with the bucket curled all the way back on the ground (hide all the chrome) to check the level. Should be in the middle of the sight glass. Is it better or worse as it heats up, or just erratic? Any leaks or oily spots underneath? Definitely see what difference your pilot enable switch makes when messing with it to see if that's your issue.
There should be a hole in the sheet metal near the right rear side of the machine with a sight glass in the hole. Like Marshall said, position the machine properly to check. Oil level could be the issue if not checked properly. When you replace the hydraulic and the pilot filters check for debris (cut filters open if you have to) and post pictures if there is debris. All Deere excavators (including mini's) are Hitachi (even though some mid size model excavators are assembled in a Deere plant in North Carolina). There has not been a Deere designed/built excavator since the 690's.
Thanks to everyone for their time and suggestions. I think I am making some progress. The manual clearly shows a site glass on the hydraulic tank on the right rear of the machine. However, with the covers open and the entire tank in sight, there is no sight glass. There are however two bolts plugging two holes aligned about 6" apart. So I'm guessing at some point in its life there must have been a sight glass arrangement there that was removed. In any event, I made a dipstick so I could set the oil level a bit below the top bolt. I could just unscrew the top bolt as a level plug, but I figured why bother and have to worry about the bolt sealing to pressure. I added about two gallons of fluid. With a 7 gal capacity, I think, that is a fair amount. The second thing I did was closely inspect the left hand safety switch. With the lock handle down, there is a tab that pushes back on the stem of a small switch. The whole locking assembly is a bit worn, so even though the arm locks down, there is enough slop that the tab can move away and open the switch. So the bungee cord he had lying there was for a reason, to hold the locking lever arm down firmly. Once I get some time, I should be able to check the spring and assembly and get it working reliably as it was designed. For now though, I put the bungee on it. I hate to change two variables at once, but everything worked perfectly between the added oil and the bungee. I'm guessing without the sight glass, the previous owner just added oil as a guestimate. I'll know to monitor it now and keep it set at at the proper level. The dodgey switch was causing it to just act weird and jerky as it bounced in and out of engagement. Thanks again to everyone. These seem like obvious problems in retrospect, but everyone's suggestions really helped me find what the problem was. Now the only thing I noticed is that the power of the front blade is low, in that it is not enough to lift the front of the machine. The bucket and arm seem to work fine digging, although I haven't tried any really compacted and rocky soil yet. I'm guessing (again) that the main hydraulic pressure is not quite what it should be. I'm hoping with an older machine like this, that I can scrounge used parts at a salvage yard somewhere, should I need them. I have a D2 dozer that took me probably 2 years to bring up to snuff, looking for $500 used tracks, etc. but it is in great condition now. This JD excavator seems to be enough for the few things I want it to do around the farm, and I can slowly fix and improve things over time. I'd love a new $50,000 one, but until I win the lottery, this old one will have to make due.
Welcome to HEF and congrats on your machine purchase. Those two bolts on the hydraulic tank are probably where the site glass was, it may have been leaking or may have gotten a hole in it. I would suggest getting a new one, just so you can visually check the hydraulic oil quicker than using your dipstick, plus undoing the cap and using a dipstick in there lends itself to contaminants possibly getting into the hydro tank. Hopefully the safety switch was your main issue.
I agree with Tags ^^^^. A sight glass kit (p/n 8050296) is only $60. I don't know if it comes with the rubber washers (p/n 449558) at $5 each. It should come with them I think.
Tags and mg2361, Thanks for the heads up on the sight glass. I actually do have both main manual, the parts manual and I had ordered the service and diagnostic manuals, so I'm loaded for bear. I've just been too lazy and engaged to open them up and study the diagrams. Now, I see the "level gauge" PN 8050296 and washers 449558. I'll order everything soon, and also dig into the cutoff switch assembly and see if I can just buy parts of the assembly or at least recondition it so it exerts reliable pressure on the switch. I'm relieved that the machine is back to where it was when I bought it. Now I need to just keep going through it, and cleaning, adjusting and repairing whatever it needs to slowly bring it up to snuff. The little I've used it, I do like the machine. It is just about the right size for what I need and it is going to be one handy tool to have around when needed. The only thing I wish it had was a hydraulic thumb. I see extra hydraulic lines running up to the top of the boom. However, I don't see any bracket where a thumb cylinder could attach. Are those extra lines for hooking up a thumb? Looks like I'd better do my homework and dig into the manuals some more.
A thumb kit from Deere would come with the bracket to attach to the arm. Yes those lines are used for a thumb or a breaker. There is a switching valve to change the flow on those lines from one way flow (breaker) to two way flow (thumb). Thumb installation would require circuit relief adjustments.
Hi Does any one have diagram on the blade control handle on deere 35zts. Lime to see whete its attached . Its not lifting up seems its let go underneath
Welcome to HEF John . See link below to parts catalog for blade control. https://partscatalog.deere.com/jdrc/sidebyside/equipment/408/referrer/search/pgId/12254599 .
Thank you. Whats eaiest way to get at it under the cab, i removed some panels and cant see anything think linkages let go
Not sure. @Juniper was working on a 35ZTS blade control issue in August , he may be able to answer how to access the linkage.
on my 50ZTS, there's a panel under the seat. you pull all the bolts for the seat, then the panels where you feet go. Crawl underneath, remove that circular plate, and you should be able to see light from above when under it. if not, time for a cleaning.