I purchased a really rough TH83 telehandler in early November after wanting one for a while. I don’t have much heavy equipment experience at all so thought this would be a good project to start with. It ran fine but most switches didn’t function. Only steer select worked and the previous owners had really done some interesting rig jobs on the cab wiring so I completely pulled everything out over the course of a month and put original parts back in and completely rebuilt the wiring harness (cab). All my switches work again except my mast tilt. I’m certain it’s not the relay in the cab, and the joystick buttons are good. I haven’t had it running but for 10 minutes since I have owned it because I wanted to make sure things were right. Now it is low on hydraulic oil, would this cause the tilt function to maybe not work since that cylinder is one of the furthest away? I plan on changing all the fluids but I did not know if I should wait until I have confirmed I don’t have to replace anything that would require me to just change the fluids all over again so my question is... If this previous owner put hydraulic fluid in the rig and it actually calls for motor oil in the hydraulic system as per owners manual, does it hurt anything if I put motor oil in it and mix? From what I got out of talking to the last owner, he was using elevator hydraulic fluid that he had a 55 gallon barrel of. I have no idea if that’s fine or not but I am eventually going to change it just so I am certain I know what is in it. The questions I have from all my rambling. 1. Would being low on hydraulic fluid cause my mast tilt not to work, but my boom lift and lower was fine (I haven’t tested the boom in/out yet)? 2. Is it ok for a brief period to potentially mix motor oil and hydraulic fluid?
1. No 2. Yes The next step for me would be to see if the solenoid that activates the hydraulics for the mast tilt is getting power and operating. Most likely it's not getting power because of what you described with the wiring mess. Do you have a wiring diagram?
Would you like one...? A Serial Number gets it for you ..........
Thank you, but I do have the wiring diagram. I suppose I will dig into that shortly. Of course I parked it where rain water collects and looks like I will be swimming/testing.
Good to know. There are 4 different schematics for the TH83 and they are Serial number range-specific. Just make sure you have the right one for your S/N. If you need a hydraulic schematic you can have one of those also. Same applies as above, need a Serial Number to get the correct one from the four options.
I believe it's the right wiring schematic. I do not have a hydraulic schematic.
Electrical Schematic for your Serial Number should be Cat Publication RENR4304. Is that what you have..? Hydraulic Schematics depend on how the machine is configured. SENR5845 is the basic schematic RENR3443/3444 are for the options. All three attached below.
My wiring schematic is RENR3404. It shows my serial as being in the field of what's compatible. Is yours a new revision? Thanks. I will take a look at this.
Sorry, dyslexia strikes again ........ correct electrical schematic should be RENR3404.
Yeah, it creeps up on me from time to time. haha. A few things. I have yet to look at the solenoid for tilt but I did put hydraulic fluid in it (about 2" from the top under the door by feet) and it's not registering on the glass inspection window on the outside which I found strange. I started it up and it booms out very slowly but to the full extent, but it wouldn't come back in. I had to give it some slight throttle so it would start to retract back in. Is this to be of any concern?
Probably a good lubrication (and adjustment) of the boom slide pads wouldn't come amiss.......... If you had an Operation & Maintenance Manual that would give you all the "how to" information regarding the lubrication. $46 from Cat for a pdf download. Regarding the hydraulic oil level, retract the boom and raise the outriggers fully. Keep filling the tank until the oil level appears between the two red lines in the sight glass.
I have an old muddy one that I will work on getting the pages unstuck on and look into that. Thanks for the help. I heard someone mention the pads before and had no idea that was something that needed servicing. I took a peek underneath it and haven't quite gotten my bearings on what is where from the schematic subframe section in relation to the actual machine. 1. In the schematic section H25, is Tilt_2 what my solenoid would be (1191180)? I'm assuming the bucket config Tilt_1 just won't be there? Here are a few random pictures. The first picture is of a few solenoids that would sit right in front of the back right tire under the subframe. Noticed some light cuts on the wire jackets. The second picture was just of a leaking area I noticed off of some kind of valve or solenoid. This area was towards the outside wall of the subframe. The third picture I noticed was a blue wire that I could not find any number on that was disconnected from somewhere. (What's the yellow jacket that's around that wire called? Is it some kind of heat/weather protective jacket?)
I went out and noticed leaking around the window gauge now that it's filled up, but no sign of any fluid in the window. Also, took pictures of the pads just for fun. Don't know what I am looking at.
Last one of pads.
I was running this through my mind and remembered that a button on one of the handles has to be pushed and then you operate the boom extension to make the carriage tilt up or down. The oil level is kind of critical on those machine so you need to make sure the boom and outriggers are parked in the correct position when you check the oil. The boom coming back slowly is pretty common. If you have a manual, look to the part that describes adjusting the chains in the boom properly. There are different kinds of material used in those slide on the boom so you should check the recommendations before applying any lube. As I recall the fiber ones were supposed to be left dry. The book will also tell you how to adjust them properly. I was always more concerned of the boom sections being straight more that worrying about the wear on the plates. I seem to recall the valves you are showing in the photos are directly under the back of the boom. A lot of times the extension cylinder would be leaking and the oil would drip down onto the valves when the boom was at a high angle. There is a plate on the back of the boom you can remove to check it out.
You posted ahead of me showing that you have the fiber pads. As I recall those don't get any lube but check with a Cat dealer to make sure. They changed their recommendations a couple of times that I know of. I thing that sight gauges has O rings on the back sides of each bolt. I kind of looks like there might be leaks above it though.
I’ll have to check the valves you’re referring to. These valves are directly under the location of the radiator. Also, on the button to tilt mast is a different configuration I think. I do know what you’re referring to also, and tried it just in case. This one is just the two buttons together I believe.
I would try snugging up those allen head bolts on the sight glass. Costs nothing and may stop the leak. Otherwise like John C suggested there are o-rings behind that need replaced.
If you consider how you value your time maybe you couldn't unstick the pages for less than $46... also with anything bought online you could bank on getting the latest updated version. The boom pads and their maintenance recommendations as JohnC mentioned would be a prime example.
I'm going to work on that shortly. Been pouring down rain on us lately. Yeah. They're not too bad actually, but I did notice it's the August 1996 revision. Maybe I should grab the newer one. Speaking of the year model, I do have a question. So I was looking on Machinery Trader and there were some very close to mine that made me put mine at a 1999 model, however I noticed that every wheel says 06/01 on them. Sure, the wheels could have came from another one during a change of some kind but are the serials usually consecutive to build day, or do they skip around?
Your machine was built on 15th February 1999. The latest version of SEBU7270 is dated 2009. That's what you would get if you bought a new manual today. Question: Have you checked the document number on the top RH corner of the front cover is actually SEBU7270..? If not, what is it..? Also take note of the Change Level of the document, that's the numbers after the dash immediately following the publication reference, e.g. SEBU7270-00 or -01.
How were you able to figure the date of build out? Do you have an internal program that tells all of that? Mine is SEBU6865-01
Build dates are listed on a Cat system I have access to. The latest version of SEBU6865 is version -02, published in 2002.
When you are saying the tilt doesn't work, are you meaning that the automatic/ self leveling "tilt" of the mast/ forks doesn't work, or/ and that the button/ lever doesn't work? If the forks start out level, and you boom up, there is a set of cylinders that "automatically" make the forks stay level as you raise the boom. Do the forks stay at the same angle in relation to the main boom, or do they change as you boom up?
Interesting. I mean the button doesn't work to allow me to tilt the forks. However, I did just realize that they do stay level the whole time I am moving the boom up and down.
Okay- now you're getting somewhere. Now you at least know that the cylinder/ mast/ fork section is working correctly, now you just need to make it run off the control lever. I think the th83 use a pilot hydraulic set up, but it may be electric. I'm going to suggest you look closer into what John C. recommended. Probably the button/ or some used a trigger, to switch between telescope/boom, and carriage/ fork tilt.
Well that's good to know. So I haven't had a lot of time in the past few days to get under the machine and figure out where the tilt solenoid is. I have a general idea and I just went and looked a few minutes ago at where I thought it was in location to #8 on the schematic and I figured out this is unplugged. These two wires coming off of this look red but they have overspray from paint and I can't make out any numbers. Schematic shows Tilt_1 should be Yellow/pink to Black/Black. However, I did find it interesting it was just unplugged with a spider web in the connector.
Good deal. Now you just have to get the handle control/ button hooked up to that, and you'll be good to go.
Get in there with a bit of paint remover. The number on the insulation of each wire repeats every 6” or so.
So I just went and did a little more exploring. I am about certain that the unplugged wire is the tilt_2 on the schematic. However it shows like it is two black wires running off of every solenoid off this hydraulic block on schematic but these are red wires. I cannot find the other end where it would plug to the harness yet. That solenoid is leaking also. Has fresh drip on it. The arrow is pointing at the bottom of the solenoid that I had pictured unplugged a few posts above. Would it hurt anything if I put some kitchen degreaser on all of this then the oil and all off? Didn't know if that was bad on the O-rings or anything.
Don't take this the wrong way, but have you ever thought of getting into that area with a pressure washer (hot water for preference) before starting to chase the wiring..? Cleaning everything could give you a much better idea of where everything fits.
Not going to lie, I was afraid to wash it off with a pressure washer around all the hydraulic manifolds and connections because I didn't know if it was hard on them. I have no experience with hydraulics and didn't know. Well, I took your advice... Spent a lot of time cleaning it up and things look a lot better.
So I got it cleaned up and I am struggling now. I can't quite wrap my head around something. I hope I explain this well, so here goes. The schematic is really confusing me. I cannot find where the Tilt solenoid is. I noticed in the schematic that the Tilt_2 solenoid is the same part number as AUX_B and AUX_A so I would be looking for similar or is it actually the exact same solenoid and it all overlaps?? There's also a weird pointless harness that attaches to the plugs that looks like it just basically adds length two the AUX_B and AUX_A plugs as it's the same color as them (BLK/ORANGE and BLK/BLUE). Like I could remove it and everything is still easily plugged in. The part on the small wire harness is 172-7895. What gets me is the schematic tells me that the Tilt_2 solenoid should be in the same location and it's a Yellow/Pink wire and I do not see that wire anywhere at all. I don't even see the Tele_Out that's Black/Brown. I know you had said this is the newest schematic RENR3404, so I have to be overlooking something or not understanding how something works because Tele_Out works just fine on the machine so it has to be hooked up. Also, none of these wires underneath it have any numbers on them at all, unlike the cab harness wires. The schematic shows that location 8 is where both should be.
Before you run this machine you might want to fix this . Looks like that nut is cutting the boom into. Bob
Good eye. Didn’t see that. I’ll have to look at that tomorrow.
I found the wires that are listed as tilt1 and tilt 2 wires on schematic but both have caps. The tele our wires have a cap too. I am really confused.