I got a call to go look at this machine tomorrow. Apparently Deere has been there and 2 other independents and no one has cured it so now it’s my turn. Intermittent tracking to one side and sometimes if you add a tiny bit of pressure of bucket curl it will straighten out but not always. Owner says it started doing this after the pumps were replaced. My first thought is to start checking pressures at the pumps and move forward from there and the owner thinks it’s a sensor or an electrical issue. I am not at all familiar with this machine and was wondering if anyone has any experience with a similar situation?
My question to the owner would be if the pumps were new or rebuilt exchange and were they factory or aftermarket? I think the gauges would be appropriate but if it is an adjustment problem on the pump, you will need a flow meter. I know those have Hitachi electronics on them but don't know for sure whether or not the Dr. ZX will work to check them.
I’m not sure why the dealer couldn’t figure it out. I don’t have a flow meter or dr. Zx. As far as adding a bit of bucket curl to even out the speed I figure it’s just slowing down the faster pump and making it track straight. I assume this is just like most excavators meaning that each pump handles drive speed on one side and they divide the rest of the hydraulics between them.
I believe the machine joins both pumps when another function is used to keep the machine traveling straight.
Yes they have a flow combiner valve in the MCV to keep it tracking straight when using a digging function at the same time. My question is, why were the pumps replaced? Catastrophic failure?
I don’t know why the pumps were replaced. I talked to the service manager at Deere and he knew all about this machine and thought that they had cured it a year ago. I guess I’ll find out the whole story in a couple of hours. The intermittent part is what gets me. Owner says it will act up for weeks and then go away for a few days and then return. In my mind that doesn’t really go along with pressures being out of adjustment.
So I went and checked it out this morning. The pumps were replaced because the input seals were leaking. They are reman pumps and we’re in it when the current owner bought it. I repaired plenty of wiring that had been twisted together and covered with electrical tape. For the life of me I couldn’t find a fitting to put in the pump the check pressure on my truck . The left side track runs slow but if I curl the bucket in or hold a little press down on the main boom the track speed will pick up. I did some more looking and found the propel pilot pressure switch had a wire that was only held together with a couple strands. Going to pick up the switch and a pressure fitting tomorrow and see what happens.
I had a more severe issue with tracking with my 892E and it was that the pump was starting to go bad (the end cap had a rough spot that would sometimes stick). Once you got the pump spooled up, it all worked ok... but as soon as the pump de-stroked you had to bump a function to get the pump to stroke.
I’m at the machine right now and I’ve got all kinds of issues. The wiring harness is such a mess I’ve disturbed something and now the throttle has a mind of its own. Sometimes it idles right up on its own, sometimes it hunts, and right now it won’t idle up at all. As far as the tracking issue, it’s tracks to one side until I hold in on bucket curl and then it tracks straight. I’m thinking that when I travel it’s not getting a pilot signal but when I curl the bucket it strokes up the other pump and straightens out. I think it’s all in the harness but I’m still digging
If you unhooked the battery or disconnected a particular fuse, then you need to re-cal the throttle.
Yup. I have the procedure. The owner bought another machine so he’s going to haul his back to his shop and I’ll get back on it in when I get back from vacation.
Hi, we're you able to solve your problem? I have 3 892e. I've owned 892s for 15 years now. So I do have a good idea of how these machines work. However I have 1 of them that has heen mistracking for around 3000 hours now. Same symptoms as you have described. Weak on left track. Rear pump is a reman, was in It when I got the machine. Front pump started failing, I replaced it with one from another working machine. I rebuild travel motor, rotary manifold. No fix. Then the swing bearing was loose so I swapped the whole carrier out for another one. Still mistracking. I've checked pressure on pumps. I've changed flow combiner valve. I've changed the main relief and track relief valve. No luck. I'm just about to change the main control valve, as I have come to no other ideas. This machine has been doing this since I got it. I kinda suspect that is why the rear pump is a reman. The guy before me probably had the same problem.
I never did. after I looked at it and returned from vacation he texted me and basically accused me of screwing up everything including his a/c after looking at his pumps. Adios muchacho. I steered clear of him. probably explains why several people had worked on it.
Okay thanks. Too bad to hear that.
Meh. It’s how it goes. A wise man once told me that there is too many good customers to worry about the bad ones. Take care of the ones who take care of you. It has served me well.
The machine had a problem to begin with no one could figure out but now the owner blames you for other problems when trying to fix the original problem and mess of wires. It will probably become a big paper weight. Hopefully he paid for the work you did.
Luckily I did get paid.