The JLG 40F Boom Lift Dilemma

[Grovecomm]

I can't find a serial number on mine, so don't know the exact production year. I have a summer project I need the machine for and don't have time to do a rebuild of anything. Hoping to get it limping along for the summer and rebuild it later.

 

[RSIGuy]

I want to give a shout out to everyone who helped me this winter especially OFF for the valuable insight into my 1976 40F. :drinkup. Pat my electrician buddy was phenomenal and we could not have done with out everyone's insight or posts.
All systems are go, she got a head to toe degreaser bath Sunday, all covers re-installed and is ready to make some money!
So, if there's anything I can do to help anyone else I would be glad to offer my services in return. I'll get an action photo when I can and post it. You can also check us out at restorationservicesinc.com. Thanks again!:salute

 

[dlindbis]

Hi all. Another new owner of an old 40f. Pretty decent machine needing some of the same TLC they all seem to. Like everyone, am looking to get a copy of the service manual with schematics and wiring diagrams. They are a bit crazy to figure out without one. The main issue that's developed is with the toggle for in/out of the boom. I have checked both toggle switches and wiring, and it all seems good up to the circuit board. I get steady voltage at the solenoids both directions, but the relay on the circuit board, which I believe runs a check valve for the cylinder, is erratic on the 'in' direction, but good on the out direction. Does power feed to this through the diodes and/or transistor on the circuit board? any help?

 

[OFF]

OFF, are the threads all universal? If so I would be wasting my time looking at others I suppose.

Looks to me like the 1106 and 7011 use the same mounting system (external mason jar thread). I think either one will work for you.

 

[OFF]

I can't find a serial number on mine, so don't know the exact production year. I have a summer project I need the machine for and don't have time to do a rebuild of anything. Hoping to get it limping along for the summer and rebuild it later.

Sounds like your machine has had a hard life, but if you got the engine to move (pistons moving in the cylinders) you should be able to bring it back. Those head bolts did like to rust up and break off alright. Certain head bolts see a lot of heat on those air cooled engines (like between the cylinders where there is no air flow).
Not much you can do except drill the broken one out and use an easy-out or other extractor on it. Heat might help. Be sure to run a tap through all the other holes, blow them out and apply something like never-seize to make it easier to take apart next time.

 

[Grovecomm]

Thanks OFF. I was thinking about no-seize but I wasn't sure they would hold their torque if using that. I feel lucky that only 1 out of 34 broke.

 

[RSIGuy]

Thanks OFF. I was thinking about no-seize but I wasn't sure they would hold their torque if using that. I feel lucky that only 1 out of 34 broke.

I'm curious how's it going? Did you get that motor to breathe fire yet?

 

[Grovecomm]

I've been away from it for a while, but I'm going back to it today. How did you know???? Maybe your perfectly timed question will give me luck. I did get the pistons free a couple of weeks ago by filling the cylinders with $22 worth of WD-40 and "encouraging" them to move. Maybe we'll be breathing fire soon!

 

[RSIGuy]

I've been away from it for a while, but I'm going back to it today. How did you know???? Maybe your perfectly timed question will give me luck. I did get the pistons free a couple of weeks ago by filling the cylinders with $22 worth of WD-40 and "encouraging" them to move. Maybe we'll be breathing fire soon!

Good guess I suppose? Good luck. You think you spent a lot on WD, wait until you change the hydraulic fluid & filter theres about a $400 in that reservoir.

 

[Grovecomm]

A gallon of WD-40 in the ACE store in Crivitz, WI cost me $28. A day later I was at Menard's in Green Bay and it was $14.

 

[sulphurscott]

boy would i be interested ? you bet i wood

 

[Grovecomm]

She breathed fire today!!!! I had to take the heads off again because the back two exhaust valves were rusted solidly open. After I finally got the stems loose, I gave her some clean fuel and much to my surprise she fired right up after having the back two pistons seized up for several years. The boom went up/down, left/right and in/out. The bucket controls need work so I don't know if it steers or travels yet, but I've jumped 98% of my hurdles!!!!! I've worked professionally on electrical and electronic control systems for the last 38 years, so I'm thinking that stuff will be simple for me.

 

[RSIGuy]

She breathed fire today!!!! I had to take the heads off again because the back two exhaust valves were rusted solidly open. After I finally got the stems loose, I gave her some clean fuel and much to my surprise she fired right up after having the back two pistons seized up for several years. The boom went up/down, left/right and in/out. The bucket controls need work so I don't know if it steers or travels yet, but I've jumped 98% of my hurdles!!!!! I've worked professionally on electrical and electronic control systems for the last 38 years, so I'm thinking that stuff will be simple for me.

That is awesome! I'm shocked that thing lives and so many of the controls are working. Seems odd it wasn't still in use.

 

[Grovecomm]

Got to the bucket today, everything worked. The only thing I didn't test was the high speed travel. I feel very lucky.

 

[RSIGuy]

Got to the bucket today, everything worked. The only thing I didn't test was the high speed travel. I feel very lucky.

I would say you're lucky! I had many more problems with mine and it was in use everyday, but no longer. The new wiring head to toe is a total success. I only have one issue left, I have put 2 high pressure seals in one of the drive motors and it still appears to be seeping a little. If it ever stops raining I could verify that. A mechanic that used to maintain it said he thinks internal parts may be worn enough to allow blowby. The biggest issue is it seeps onto the tire delaminating it and pretty soon I'll be on a tube (it's foam filled so it can't go flat) but don't want to replace it until I get it solved. If you or anyone out there runs into a drive motor with 2 hoses (plus brake) I would be interested it it.

 

[mf1135]

Hi guys,
I have a 40G that i'm working on and when I drive it and try to steer it the machine stops moving until you let go of the steering switch then it moves again. It was working before then it just started doing that? Anyone have any ideas?

 

[OFF]

well, the first thing I would do is hook a volt meter up the ignition terminal of the basket controls, see what voltage is with the engine running, then while driving, and when steering. If the voltage drops off drastically when you steer, you've got a short t ground someplace that's hoggin all your power.

 

[RSIGuy]

well, the first thing I would do is hook a volt meter up the ignition terminal of the basket controls, see what voltage is with the engine running, then while driving, and when steering. If the voltage drops off drastically when you steer, you've got a short t ground someplace that's hoggin all your power.

I would agree. We had the same problem before we rewired, a little hesitation or even a stopped in it's tracks.

 

[terasque]

Hello again guys

I had to rewire the 40f I was working on. The basket control box was smashed and the wires looked like a plate of spaghetti. Lower box was the same. I sent the joysticks out to the shop in bowling green ohio for rebuild. All seems ok except the racine valve bank. One coil has a broken wire and all three banks only function in one direction, up only, forward only, and one swing. I could use some coils for sure if anyone has a source for some. I found the entire bank but no parts (4700 $ from jlg). I don't remeber seeing comments on the racine controls in the forum but I might have missed it. Some input on that would be nice. All three joysticks will produce voltage in both directions so I am thinking bad coils maybe? Definitely need one coil for sure to replace the broken one. Thanks again everyone.

 

[OFF]

Hello again guys

I had to rewire the 40f I was working on. The basket control box was smashed and the wires looked like a plate of spaghetti. Lower box was the same. I sent the joysticks out to the shop in bowling green ohio for rebuild. All seems ok except the racine valve bank. One coil has a broken wire and all three banks only function in one direction, up only, forward only, and one swing. I could use some coils for sure if anyone has a source for some. I found the entire bank but no parts (4700 $ from jlg). I don't remeber seeing comments on the racine controls in the forum but I might have missed it. Some input on that would be nice. All three joysticks will produce voltage in both directions so I am thinking bad coils maybe? Definitely need one coil for sure to replace the broken one. Thanks again everyone.

Hi terasque, the JLG part number for those coils is 7000406. I don't have any left but if you give your dealer that number he should be able to order them for you. It's amazing what you can still get for the "F series" when you've got the part number. I should have a Racine part number for those coils as well. I'll dig around for it.

Another very valuable part number - 7004831 That's the seal kit for pilot section (servo section) of the Racine proportional valve.