1994 JLG 45HA Questions

[TheFixer]

Hello to all.

I just purchased a used 1994 JLG 45HA and I have a few questions and things I would like to fix on the machine.

I do have a couple operations moving slower than the rest, so I bought the test harness for the controllers so I can re-calibrate/test them. I put a pressure gauge on, and it builds pressure, but slower than the rest.

One of the questions I have, is for the drive. It is only 2WD, but it seems that the motors are only linked together (hyd with the divider valve) in the forward direction. Has anyone ever looked at adding another divider valve to the reverse line, so both wheels are driving in the reverese? I will be doing quite a bit on grass, and I was hoping the 2WD would be enough for what I am doing, but was disappointed in the reverse driving.

The drive alarm does not work. There appears to be a notor controller for it that is burned up. When I look up the part, it's $580. I can't see spending that kind of money on it, but would like to fix it. Anyone know of a newer modern kit that would work? The alrm does work wit 12V on it. I traced the wires back, and ihave 12V and the FOR and REV feed wires, but I assume they are from the controller, and not 12V feeds, so something needs to monitor those and drive the alarm. Hence the $580 controller.

Also, it has a 120V box at the platform. There is a 120V plug in the engine compartment. Is that just an expensive extendsion cord? It does not have the genererator, but I wish it did.

Instead of the expensive $2K generator, anyone ever add an inverter to the machine? I am possibly looking a doing that sometime, maybe in the spring.

Other than that, it seems to be a good machine. I will be looking into tires possibly. They look like crap, but they are foam filled, so they work.

Thanks for any help. There is a lot of good info on here that I have been reading thru.

 

[trainpilot]

We've got a 45HA electric which I am considering converting to gasoline power. I am just starting to search for those who have gone before me. Re: the 120 volt question: It is just really an extension cord, albeit much safer and more convenient than one dangling from the bucket. I use a little Honda suitcase generator that just rides on the top of the battery compartment. It's pretty quiet, especially if pointed the right way. I know on our machine, the cord for 120 isn't heavy gauge, so I limit load to about 15 amps(which is about all the little Honda will do.

 

[willie59]

Welcome to HEF TheFixer. A 2 wheel drive machine isn't the ideal machine for running on grass/soil, especially if it's a rigid frame machine that doesn't have articulating steer axle. On a 2WD rigid frame machine the slightest hump on the ground will cause you to loose traction. Yes, the flow divider valve fitted in the drive circuit helps a bit with this problem, but it's no where near as good as a 4WD with articulating steer axle. Is a drive motion alarm something that you require? Is this a Ford gas machine or a Deutz diesel? Does the platform controls have PQ controllers or OEM controllers?

 

[TriStarAerial]

Hello to all.

I just purchased a used 1994 JLG 45HA and I have a few questions and things I would like to fix on the machine.

I do have a couple operations moving slower than the rest, so I bought the test harness for the controllers so I can re-calibrate/test them. I put a pressure gauge on, and it builds pressure, but slower than the rest.

One of the questions I have, is for the drive. It is only 2WD, but it seems that the motors are only linked together (hyd with the divider valve) in the forward direction. Has anyone ever looked at adding another divider valve to the reverse line, so both wheels are driving in the reverese? I will be doing quite a bit on grass, and I was hoping the 2WD would be enough for what I am doing, but was disappointed in the reverse driving.

The drive alarm does not work. There appears to be a notor controller for it that is burned up. When I look up the part, it's $580. I can't see spending that kind of money on it, but would like to fix it. Anyone know of a newer modern kit that would work? The alrm does work wit 12V on it. I traced the wires back, and ihave 12V and the FOR and REV feed wires, but I assume they are from the controller, and not 12V feeds, so something needs to monitor those and drive the alarm. Hence the $580 controller.

Also, it has a 120V box at the platform. There is a 120V plug in the engine compartment. Is that just an expensive extendsion cord? It does not have the genererator, but I wish it did.

Instead of the expensive $2K generator, anyone ever add an inverter to the machine? I am possibly looking a doing that sometime, maybe in the spring.

Other than that, it seems to be a good machine. I will be looking into tires possibly. They look like crap, but they are foam filled, so they work.

Thanks for any help. There is a lot of good info on here that I have been reading thru.

Just had one of these come through our shop. If you don't have the SkyPower option, yes that is just an expensive extension cord. OSHA won't let you have cords dangling off machines, so that's why it's there. You COULD run an inverter but its doubtful the electrical system that it comes with will do much more than it already rated for. Harbor freight can help you with a genny on the cheap. 2WD on grass, is gonna be tough unless its high manicured and not super soft. Thats honestly for turf/pavement only.

If you need some help with the JLG controller/alarm issue, send me a PM. We deal with that stuff all day long and the $580 price tag is retail. You obviously don't want to pay that.

Good luck!

 

[trainpilot]

Fixer, We have a similar machine, though battery powered. Three of the tires have foam, one has air, and they're all about ready to give up the ghost. I've been looking into new tires for it, maybe some skid steer wheel/tire combos. I wouldn't mind a little wider track as it's a pretty compact machine for its capabilities. One tip I've learned using ours on less than ideal ground is to be aware of the load on the wheels/balance of the machine. If you're not extended, most weight will be on the wheels under the counterweight. These will have the most traction. You might be able to make progress running machine "backwards/rotated 180degrees". It really isn't very good for soft or uneven conditions. If you find a good deal on wider tires, let me know.

 

[TriStarAerial]

Fixer, We have a similar machine, though battery powered. Three of the tires have foam, one has air, and they're all about ready to give up the ghost. I've been looking into new tires for it, maybe some skid steer wheel/tire combos. I wouldn't mind a little wider track as it's a pretty compact machine for its capabilities. One tip I've learned using ours on less than ideal ground is to be aware of the load on the wheels/balance of the machine. If you're not extended, most weight will be on the wheels under the counterweight. These will have the most traction. You might be able to make progress running machine "backwards/rotated 180degrees". It really isn't very good for soft or uneven conditions. If you find a good deal on wider tires, let me know.

Even with the wider tires train, you are going to run in to a torque issue once you get in to the sloppy stuff.

 

[adoll]

Have JLG 45 HA and steering doesn't work. Neither does the front leveling. Are they tied together somehow?

 

[adoll]

Can I check the steering solenoids with out the coils? I have power to the at the coils when activated?
Thanks

 

[willie59]

The steering circuit on a 45HA is an independent circuit, not connected to any other hydraulic circuits, pressure is supplied to the steering control valve from the rear piggy back pump, the steer valve is open center in neutral so when steering isn't in use oil returns to tank. There should be a small pin in the center of the solenoid spool that you can place a small phillips head screwdriver on the pin and push the pin inward to manually operate the valve and verify the pump is working.

The hydraulic cylinders on the steer axle aren't really leveling cylinders, they're axle lockout cylinders to stabilize the machine when you have the boom/platform over the side of the machine. There is no manual control for the lockout cylinders, they're controlled by the lockout valve mounted on the base frame of the machine.

 

[adoll]

Thank you

 

[adoll]

I pressed the pins in on the steering solenoid and nothing happens . I tried adjusting the pressure, nothing again. Where can I buy a pressure gauge with the proper fitting and hose? Since the pump is in three sections can I buy just the steering section and where? Thanks

 

[willie59]

Pretty much any hydraulic hose shop that makes hoses can supply you with a pressure gauge, hose, and necessary fittings.

You could have a failed pump, failed main relief valve in the control valve, spool in control valve could be stuck and won't move, or the piston seal in the steering cylinder has totally failed. I think the first thing I would do is disable the ignition for the engine so it won't start, then disconnect the pressure supply hose to the control valve and place the hose in a bucket, crank the engine and see if it's pumping oil. If it is, re-connect pressure supply hose and disconnect hose at steer cylinder, drop them in a bucket. Enable ignition on engine, start it and try the valve using both power to the coils and also try pushing in the coil pins manually, see if you get any oil out of the steering cylinder hoses.

 

[adoll]

Checked the pump pressure at steering valve check fitting and the pressure is only 125 lbs. So I guess that means the back pump is bad. Do you know if I can remove the four bolts that hold the three pumps on and just remove the back pump? Do you think I can get it rebuilt or buy new? Do you know where to buy at the best price? Thanks

 

[willie59]

Checked the pump pressure at steering valve check fitting and the pressure is only 125 lbs. So I guess that means the back pump is bad.

Not necessarily, it's a gear pump feeding an open circuit valve. You could simply have a failed relief valve in the steering control valve.

What you need to do is disconnect the hoses that are connected to the control valve that feed the steer cylinder. Cap the two port fittings on the control valve with proper JIC caps. Start the engine, engine at idle, and either power up the two coils (one at a time), or manually push the pin in on one of the solenoid valves, see if your pressure is there. If not, you're going to have to get your hyd hose shop to rig you up a test hose.

Disconnect the pressure supply hose (from the pump) that connects to the control valve. Have your hose shop rig up a ball valve that will connect to that hose, then supply you with a length of low pressure (return) hose that connects to the opposite end of the ball valve and run that hose to the hyd fill port on the tank. You could even rig up your gauge with a Tee fitting on the pressure side of the ball valve to monitor pressure. I would recommend a high pressure steel ball valve to do this because they can take the pressure that brass ball valves can't, but I have done this with a brass valve, just be careful. Once you get this rigged up, make sure the ball valve is open and start the engine at idle. Make sure the return hose in the tank doesn't pop out or you'll dump oil everywhere. Start the engine at idle, slowly close the ball valve and either monitor pressure on the gauge or see if it starts loading the engine. If you get pressure, pumps is good and likely have a failed relief. No pressure, pump toast.

 

[adoll]

It's not the pump . Great pressure. Took the steering assembly off. The coils are week. Won't pull the pins. Thinking of buying assembly 4640475 for $1180. What do you think? Also the pressure does not build up in the unit. Thanks for all your help. I really appreciate it.

 

[willie59]

If that's the complete steering control valve assembly that doesn't sound like a bad price for a complete valve. I just had to replace a small tandem gear pump and a solenoid valve cartridge, just the coil and the cartridge, on a Komatsu CD60R crawler dumper, the pump was 3,700.00 and the solenoid coil/cartridge was 574.00.

 

[adoll]

Took steering control apart and put new o rings in. Now the steering works but when I turn it left or right it keeps going all the way and will not stop when I release the switch . So to steer it I have to jog the switch to keep it straight. Thanks

 

[willie59]

When you say you took the steering control apart I assume you mean the control valve for steering? If yes, how deep did you go into the disassembly of the control valve, what did you take apart? Is this the FPS solenoid control valve or a Racine solenoid control valve?

 

[adoll]

It has a Racine Valve 4640375. I took it all apart including the spool and put all new o rings. When I had it apart I found there was a return spring missing on one side. It looked like someone had it apart before me. Also the solenoids where frozen to the body and I had to use WD 40 and work them off. Maybe the spool is worn and it won't return to the neutral position. I set the pressure for 1700 lbs. When I move the switch it turns that way but when I release it keeps on going till it turned on the way. It does it both ways. I can use it but I have to jog it back and forth to keep it straight. Thanks

 

[willie59]

If one of those neutral centering springs is missing it can't work properly. Those type valves require the spool move freely, no tight spots or binding, and it requires a centering spring on each side of the spool to make it shift to center (neutral) when the solenoids are not powered up. There should also be a spring seat washer between the springs and the spool. Until you get the correct components inside the valve I can't see how it will ever work correctly.