I am having a problem with my 40ha it will rev the engine when you move the joystick but will not go forward or backward. Had the controller checked it was bad so i put a new one on but am still having the same problem. it is a single controller for forward and reverse and toggle switches for the boom and steering controls. any help would be greatly appreciated. thanks
Welcome to the forum dscont. :usa Was your machine driving properly before the drive controller went bad? How did you determine the controller was bad. Where did you obtain a new controller.
Machine started acting up a little at a time it would be traveling along and then kind of rratically stop You could move the stick back to neutral and then go again. Then it finally quit moving all together. I took the old controller to the jlg shop and he put it on one of their machines and it did not work that machne either. So i ordered a new controller through them and still no go. Thanks for the help
Ok, got it. There's a couple of things that can cause your problem. It sounds like the controller has input voltage as it activates the throttle, but it wouldn't hurt to check that you have good voltage at yellow wire going to pin 3 of controller harness when you depress foot switch with ignition on and engine not running. If that's good, you should be able to move controller off center and stroke the controller and see voltage on terminal 16 (drive rev) and terminal 21 (drive fwd) at platform terminal strip. You probably won't see 12V on these terminals, but you should see voltage when you stroke controller. If you see voltage on those terminals, you can move to the lower control box and check the voltage at terminal 16 and 21 of lower control strip when stroking controller. If you read no voltage (or low), probably have a problem in the control cable from platform to lower control box. If you read voltage, check the two colored wires (not black) at the plug connection to drive pump servo when stroking controller. If you didn't get a voltage reading at terminals 16 and 21 at platform terminal strip, it could be the controller needs adjustment. I'm thinking that PQ controller has four adjusting screws; Lo, Hi, Mid (or Threshold), and Ramp. Have the work area as quiet as possible, rotate all four screws CCW until you can hear a faint clicking when rotating screws, they are then adjusted fully off. Start the engine, depress foot switch, lift safety lock on controller handle and move controller until the shaft of control lever is appx centered at the edge of the hole that safety lock locks into, this is "notch out". Hold the lever in that position and turn the Lo screw CW until the machine just starts to move and no more. Then stroke the control lever fully in the same direction you did notch out. Turn the Hi screw until the machine starts moving. Keep turning screw, it will increase in speed, stop turning screw when machine is no longer increasing in speed. Release drive control lever and stop machine movement. Select the creep mode with creep switch. Depress foot switch, stroke control lever fully. Adjust Mid (Threshold) screw CW until machine moves at a nice, easy, slow speed. Release lever, stop machine, turn creep switch off. The last adjustment is Ramp, which adjusts how fast (or delayed) the machine comes to a stop when you have control lever fully stoked and simply let go of it and center it. Right now, if you do this, it will come to an abrupt stop. Do an initial adjustment by turning the Ramp screw CW about 10 turns. Then drive machine (low throttle) with control lever at full stroke, then let controller go (brace yourself before you do that). If it still stops abruptly, turn the screw CW 2 more turns. Keep adjusting until the drive makes a delayed stop when releasing control lever. Once you find that spot, adjust the screw in/out until the delay is what you want.
ok finally quit raining so i went out today and am getting a small amount of voltage at 16 & 21 Lift is no longer reving up but it did release the brakes that seloniod is clicking . Tried adjusting the controller with no luck. I am getting voltage at the lower box on 16 & 21 also. What do you suggest now? ps thanks for the help also i hooked up the old controller and am getting the same response out of the brake seloniod but nothing on 16 & 21
by the way the new controller has 5 settings lo, hi b, hi a , mid & rm
I was wondering if it might have that type controller, but I didn't want to muddy up my response with even more info if you didn't have that PQ controller. As with other style PQ controller, all trim pot screws must be backed off (CCW) until you hear the pot "click", or 32 turns if no click is audible (which it is very faint). Lo is adjusted using same method, notch off, adjust CW until machine just starts to move, not fully moving, just begins to get a reaction. Hi A and Hi B are for each respective drive (fwd/rev). Stroke the controller fully, and you should see an LED lamp light up at the respective trim pot, either A or B. Which ever LED is lit, adjust that trim pot to until machine no longer picks up speed. Move control lever fully opposite direction and the other Hi LED will light up, adjust that trim pot using same method. Flip Creep switch to select creep mode. Stroke controller (either direction) fully, adjust Mid until desired slow moving speed is achieved. Turn creep mode back off, standard drive mode, adjust ramp using same method as previously noted. I hope this helps.
many thanks i will try that in the morning. wonder why the throttle is no longer responding
Did someone inadvertently flip the High Engine switch off?
no already checked that and even checked ther is voltage through the switch
finally got back to this machine I have adjusted the controller but machine still won't move. I have the brakes released and with the motor running nothing happens now the engine doe not even rev to high speed. When the machine is shut off i can hear clicking and then something humming around the engine whe i stroke the controller. Any ideas? Thanks for any help in advance, Dale
And you still have a voltage reading at terminals 16 and 21? Have you tried checking where those two wires go to drive pump servo? Here's a drive pump from a 40RTS, similar setup. On this one it's the orange and the blue wires, your color code may be different, the brown wires are ground/earth. If you do read some voltage at the colored wires, I think you can remove the square cover on top of the servo and view if the servo moves the pump control shaft when operating controller.
thanks willie i will try that today yes i still have power at 16 & 21
OK just checked that servo (Thanks for the picture ) it has 11.8 volts to it when i stroke the controller. The servo is making a load humming but does not seem to be moving.
Don't think I've ever heard one of those servos doing what you're describing, not sure where this is going to take us. The servo is basically an electromagnetic coil that operates the pump output control shaft. It holds the pump shaft in the null position (no pump output) when drive is not selected, then when you select drive with the controller, it moves the pump shaft in the appropriate direction to provide fwd or rev pump output. One thing you can do with that servo is operate the manual output lever that's located on the servo coil, the black plastic box that the wiring harness goes to. Here's another pic of the 40RTS servo, kinda hard to get a clear pic of this unit because it's tucked in behind the propane vaporizer on the RTS, but you'll get an idea of what to look for. The servo manual control lever is a small plastic lever on the end of the servo coil. You can move it left or right of its center position and it will cause the pump to react in the direction the lever is directing. You could power up your brake release solenoid to release the brakes and move the machine using this manual lever. Just be extremely cautious so as to not let machine run over you. If operating the manual lever won't make pump operate drive, I'd suspect you have a pump problem.
Well fired up the machine, i already have the brakes released , moved the plastic lever on the servo and machine did not move ? You have been a great help this far thank you. now what do you think? All the other hydraulics work fine booom controls, steering everything else just no drive. Is this a double pump or something similar? Is the drive pump seperate from the control pump? Thnaks again for the help.
Well, I think it's time to send it to a pump shop. It could simply be a problem with the servo, could be a problem with the drive pump as well, I'd let an experienced person check it out and repair it if necessary. Call Ron at Fluid Power International and tell him you have a Sunstrand bi-directional pump from a JLG that needs repair, I've sent a good pile of pumps to him over the years with good results, they even cover the cost of return shipping. http://www.fpihydraulics.com/index.html There is actually three pumps on your machine. The bi-directional drive pump is connected to the flywheel housing. It's not capable of keeping itself filled with oil so it has a charge pump mounted on the rear of it to feed oil to the drive pump. Looking from the outside, these look like a single unit, but it's actually two pumps, both part of the drive circuit only. The third pump is the work equipment pump for all other hyd functions, it's a gear pump fitted to the rear of the charge pump on main drive pump unit.
I have a JLG 40 FR in my shop with a veriety of issues. Looking for wiring and hydraulic diagrams,
I understand I have to make 3 posts in order for you guys to send me any files. One problem I'm having is that sometimes when I switch from "Ground Controls " to "Boom Controls" the engine wants to shut off.
The FLG 40 FR moves real slow but engine doesnt seem to be laboring, appears to be a hydraulic issue, so week it barely crawled over the concrete lip into the garage. And when you first try to move it the one drive wheel seems like its locking up. I also need some help with the engine high speed throttle solenoid. This is the first time I've worked around one of these, I'm not even sure what function activates the high engine speed solenoid.
Manuals on the way Groundwrk. Welcome
Thank You , OFF . As im sure you know, they will be a big help and I didn't know where else I would be able to find them. Its a great thing there are sites like this and folks like you that take the time to help!
Groundwrk - I still need you to message me with your email address so I can send you the manual PDF's. I can't send attachments from on the on-board email system inside the forum.
Sorry OFF, I didn't realize,new to this forum stuff. my email is [email protected]
Got it groundwrk. Thanks You may want to edit your email address out of the above post. I'll get you those manuals very shortly
Thanks, I can't seem to edit, no icon, must not have that privelage yet!
Finally got the pump off it is completely scared up. But the oil seems to be perfectly clean . I guess i will drain the oil , flush the system, change filters and then put the rebuilt pump back on . Anything i am missing or should be looking for?
Be sure as willie said, to electrically release the brakes by jumpering the brake solenoid with 12v + and ground. Many people believe they are releasing the brakes by reversing the plate on the drive hub. This does not release the brake but simply pushes the sun gear out of the planetary gearing. It will definitely not drive if this is the case.
Good news after 2 years of piddiling around with it finally installed new pump and everything works great. Thanks for all the help.
Good to hear you got it sorted out dscont, thanks for the update.
Willie59 (and whoever else can lend some help) - My neighbor/friend has the same machine (40 HA) with the exact same problem as DSCONT's machine. We have replaced the joystick with no luck. I have measured DC voltage on the main terminal strip on positions 16 & 21. Both correspond to the movement of the joystick but in a specific way - when the platform drive joystick is slowly pushed forward the voltage on terminal position 21 slowly increases linearly from roughly 3 volts to almost 12 volts depending on how far the joystick is pushed forward in reference to ground. The same happens on terminal position 16 when the joystick is pulled backwards. This seems to work perfectly. The wire on 21 (forward) is BRN/BLU coming from the platform. It is also BRN/BLU leaving the terminal strip towards the engine/pump compartment. For position 16 (backward) it is BRN/RED coming in and BLU/RED leaving. Still everything makes sense. I don't have a good schematic to know if these two wires are the same two middle wires at the drive pump servo harness but the color code is the same (with BROWN wires on the outside to make up the full complement of a four wire harness). This is where it gets really weird because when I measure voltage on the drive pump servo harness (unplugged from the drive pump servo) these wires go pretty much instantly from no voltage to 12 volts as soon as the joystick is pushed forward (on BRN/BLU) and the same for backwards (on BRN/RED). It's not a gradual increase in voltage like it is on terminals locations 21 & 16. If these were the same wires I would think they would respond the same.....or maybe they don't because I have the servo unplugged when I'm measuring the voltage.....? Sorry - I had not thought of this possible situation when I was testing earlier today. The drive pump servo is underneath the main pump on this machine which makes it a little tough to get to. I am assuming you would recommend the same - try to get to the servo and see if we can manually operate it....? Also it should be noted that the RPMs of the machine do not shift even in the slightest when we try to drive the machine. There is absolutely no laboring of the engine as you would expect when a function calls for hydraulic pressure off the pump meaning that it appears the pump is not coming out of the neutral position at all. I will try to get some pics of our situation so that you can see what we are up against. Like DSCONT's issue all other functions work great on the machine but I understand they all use the third (most rear facing) pump to operate. I have questions on performing some troubleshooting on the pump hydraulics. I do have a hydraulic test kit as I have done testing on excavators before. I will wait for any comments on my initial post before I ask you questions regarding the any sort of hydraulic testing and the expected results. We're really hoping that it is not an issue in the pump as I'm not sure who to bring it to for a rebuild here in NH/ME. Thanks, Scott
It's been way too many years since I've worked on those machines to recall much about troubleshooting, but I can say you can't measure voltage input to the servo of the drive pump with a typical volt meter as that signal is PWM (Pulse Width Modulation), the only way you can measure PWM is with an oscilloscope. I can't recall if the servo on those machines had a manual lever on it to test pump reaction, even then it won't move as the brakes are engaged, but it would load the engine confirming the pump can output. About all I can offer, if you've replaced the joystick, confirmed the wiring is good, I'd be pulling the pump and send it to a pump shop to have it gone through as I never messed with those things, I always left that for the pro's who have the tools and experience to work on them.
Willie59 - Can you confirm that positions 16 and 21 on the main terminal strip are wired directly to the drive servo motor? Does anyone have a good schematic of this wiring? We have a few schematics but they are tough to follow. Thanks, Scott
From the diagram I'm looking at, platform terminal 16, drive reverse, brn/red wire down boom cable. Platform terminal 21, drive forward, brn/blu wire down boom cable. Brn/red should go to terminal 16 and brn/blu should go to terminal 21 at ground station terminal strip. Brn/red and brn/blu go to pins B and C respectively at servo connector, pins A and D should be brown ground wires at connector.
Perfect. That's exactly what we found. Now the question would be should we unbolt the servo unit to see if the mechanism that changes the pump functions to the drive lines actually works when the joystick is pushed forward and back? I would think there is a mechanical arm that slowly changes a variable valve inside the pump to allow for slow travel that ramps up to fast travel in each direction. Does anyone know if this can be observed with the servo unit off? Assuming this can be observed and the function is operating correctly the next step would be to verify the pump performance. There is a 9/16" plug on the top of the pump. I was hoping someone may know what the expected hydraulic pressure should be when the pump is fully engaged in drive mode? I'm thinking maybe around 2500 PSI? I plan to connect my excavator hydraulic test gauges to this port to observe the various pressures. Thanks, Scott
I'm not the person to answer those questions as I've never tried that before.