Terex R070T 2016 No hydraulics, motion, arms or auxiliary? Runs only..

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Aug 1, 2020
First post, just found this group and hoping I can leverage someone else's experience to get me operational again. ‐-----‐---‐-‐- Don't know why my separate paragraphs do not show when posting, but they do show when typing data in. Sorry about that...----- Just got this mini track machine used with 885 hrs on it. Visually in nice shape, but I only put on 9 hrs til it broke down. Was out brush mowing for a couple hours 2 days ago in rough newly cleared wooded area and all machine hydraulic functions suddenly stopped working while mowing slowly.. -------------- Would not move forward or backward, no arm or bucket/mower lift motion, no auxiliary hydraulic function. Engine remained running, no warning lights on dash. Fortunately arms were down in mowing position, so I could get out the door instead of rear window.-------------- Shut it off and got off machine and checked everything visually, hydraulic fluid level and clarity, safety interlock 10 amp fuse, checked door switch movement and all visible wiring and hoses. Nothing appears problematic. -------- Got back in, started it again and it moved about a foot or two. Then all hydraulic functions simultaneously stopped working again. Thought maybe it might be a loose wire I had jostled since it had that momentary recovery. ----------- So, went through all the same motions again, shut it off, jiggled door switch, examined lift bar magnet switch. Bounced on the seat, looked for any bad wires or hoses. Got in and fired it up again. No hydraulics still. Not even momentarily. Acts just like it would if door was open or lap bar was raised. Starts, runs, lights, horn and heater all work, but no hydraulics at all. Does not even try to move.----------- Have acquired the operating, service and parts manuals and believe in starting with the simple stuff. In this case that being the safety interlock system and suspecting (hoping?) one of those components is disabling all the hydraulics through the safety interlock solenoid. --------------- Took the seat out and jumped the wires on seat switch. No change. Jumped the bar magnetic switch. No change. Held the door switch in firmly by hand. No change (didn't try jumping it yet cuz requires dash removal to get at wiring apparently). ------------------ But, I suspect it likely is not the door switch anyway. That would just be too easy. Probably the safety interlock solenoid, which allegedly would disable all the hydraulics just as if safety bar was up or door switch was not compressed. Hard to tell from the manuals but I suspect if I remove panel behind the seat I can find the interlock solenoid there. That the only way to access it? Can that be jumped and am I correct to assume it is positive/hot and not a ground wire running to it?------------------ Anyone else had this problem on this R070T Gen2 machine? I have pored over internet posts and found various other brands/models with similar problem of hydraulics partially or fully disabled, but it sounds like the repair processes and components of safety system differ somewhat.‐--------------- I did read a post an hour or so ago (different brand machine) in which it was suggested to leave engine off, but with ignition switch on so you can hear if the solenoid is working when lap bar is pulled down while door is closed and sitting on seat (if solenoid is working...), which I will try once daylight arrives.‐‐-------------- Though that would only tell me that the 3 switches were all ok, as I think from past experience that the solenoid could still click without being functional, at least on starter solenoids... But, it should eliminate all the switches as the problem if it does click though,------------ There are some relays in the fuse box too, but I don't know if any of them are involved in the safety interlock system. Anyone know, and if so which relays are they? Manuals identify glow plug relays, but not all of the relays in the fuse box.------------------------ I have ordered new solenoid coils (but why are there apparently 3 solenoid coils - whatever those are - required for service in the parts manual)? One for drive system, one for lift arms and bucket and the other for auxiliary hydraulics? Or one for each track drive and the other for lift and auxiliary hydraulics? ------------------- I am just learning this stuff, as I have not had to deal with hydraulic problems previously. Also solenoid itself is also ordered. Will put them on the shelf if that is not it, but the delay in machine operation warrants getting them so I don't lose any more working time. And they will probably fail at some point anyways since they get a workout so often. Could be a pump problem also I suppose, but that is too costly to contemplate until I know the interlock solenoid functions.------------------ I have a multi-meter though not real sure how to use it to test switches and solenoids. Guessing it is just a continuity check to wire leads on each with door switch compressed, door bar down and seat switch compressed should all show unlimited resistance by themselves when in active positions. How do you test the hydraulic lockout solenoid itself with a meter or jumper wire to see if it is operational? Or could it click and still not be working anyway?------------- Thanks, Mike

Jim A

Well-known member
Nov 28, 2022
Check plastic coupler on flywheel to pump splines .
May be stripped or pump engagement gear loose slid off input shaft.
Motor must come out to check.
I have one all apart now.