The JLG 40F Boom Lift Dilemma

[coopequipment]

More pics.

 

[coopequipment]

Some of what I have been working on.

 

[coopequipment]

It is getting some (a lot) of much need tlc. Most was apparent when I looked at before purchasing. The big surprise was the engine, seller said that it ran but needed a tune up, sounded good, no knocking, not much oil smoke, but seemed weak. Got him to come down 1,500 on price, got it home checked out the functions all worked with the help of jumper wires for testing (I knew the basket control cable was shot) decided to check out the engine, only running on two cylinders, no compression on 3 and 4,(well now) pulled the heads, two burnt exhaust valves, rust pitting on the cylinders. Wisconsin engine parts are expensive. But it is going to live again.

 

[coopequipment]

It is getting some (a lot) of much need tlc. Most was apparent when I looked at before purchasing. The big surprise was the engine, seller said that it ran but needed a tune up, sounded good, no knocking, not much oil smoke, but seemed weak. Got him to come down 1,500 on price, got it home checked out the functions all worked with the help of jumper wires for testing (I knew the basket control cable was shot) decided to check

 

[OFF]

would you like a VH4D shop & parts manual? Very nice work on the panel btw

 

[coopequipment]

I downloaded them off the internet, but thanks. I believe it is a 1976 model. Rims were date stamp in late 1975, controllers had a 1976 date stamp on them. Thanks, it is time consuming, but rewarding.

 

[coopequipment]

Also working on making an electrical basket rotation system, simpler than running hydraulics.

 

[Scooter.crew]

I have a 50f that worked for the most part until the engine gave me too many problems. I got a great deal on a 3 Cyl Yanmar Diesel and made the swap. Had to do some modifications to get the radiator to fit but could not be happier. Uses much less fuel than the gas engine. Actually quieter than that air cooled gas pig. Starts every time, etc. Now that I have a reliable engine, I have been trying to figure out the right RPMs. It has a governor and I set it up to run at 1400 RPM for idle speed. Right now I have a throttle cable to speed it up but plan to install a solenoid for high engine at 2400 RPM but I could make it anything I wanted up to 3200. Though in testing, the only time I would want a higher engine speed is for driving. But every function is working a little different. When I go up and down the speed stays governed at 1400 RPM. If I have it at 2400, it bogs down to around 1800. Telescope tilt and rotate don't seem to put too much stress on the engine and it pretty much stays at whatever RPM I had set. At the end of the day, the only time I would ever want more than the 1400 RPM is for drive. It drives at whatever speed I have the engine going the engine does not bog down at all, just drives faster or slower. But swing is where it gets interesting. No matter where I have the speed set, left or right swing bogs the engine down to around 1000 RPM. So I believe the motor is maxed performing but putting alot of stress on it. It would not seem that the swing should require so much power.

Any thoughts on the RPMs I am using or the reason the swing is taking so much power?

 

[OFF]

Scooter.crew,
The swing actually has restrictors in-line with the hoses as they leave the valve body. This is to slow the swing down to a manageable speed. That's what is bogging the engine down. Pressures might be set a high also. There is also a by-pass block on the swing to limit swing pressure in case of emergency/accibent.

The Yanmar makes a very nice little conversion. Good choice. And the diesel will run at least a week on the fuel tank of the 50F that the gas engine would burn through in 8 to 10 hours. Good job.

 

[Scooter.crew]

Thanks. Another issue maybe you can help out with. I have PQ remote controllers. I replaced one of them a couple years ago, new one worked great. I just replaced another one but this time I was able to find just the control board from Aerial specialists for half the price of the full controller. Got it all hooked up and now is works fine, however, there is a delay in turning off. When I move the lever the lift immediately responds, but when I center it, there is a delay in stopping movement. Even if I go full opposite direction there is a delay in changing direction. Both directions are the same. Are you aware of this problem? Is this a defect or something that can be adjusted. There are 3 small adjustment screws on the potted control board labeled Hi, Low, and Ramp.

 

[OFF]

What you have there is an updated controller from a "H" series. What you describe is adjustable. The adjustment is called "Ramp". There is a special harness to install between controller and its plug-in while setting it up in series, in milliamps.
BUT
You can wing it. With your small flat blade screw driver, turn the ramp screw about 5 turns in one direction. If it gets better, turn 5 more. If it got worse, turn it 10 turns in the opposite direction.
It takes lots of turns to get any action.

 

[Scooter.crew]

Thanks for the help. I had turned the screws but I didn't know I had to turn them so much so they didn't make a difference obviously. Now it works well, if fact i was able to adjust the min screw as well and now I have much more control. Before is was like a switch, all or nothing, Now the controllers work as advertised and are actually proportional.

 

[outsider]

Hi All, Bought a 40f a while back and didn't even know who made it or the model number until recently when I saw another one for sale online as it had no tags or markings on it. Mine is an early one with serial #711424 if I read it correctly as it is stamped very lightly in the frame. Mine also has no "controller" on it as all of the switches are wired directly to the valves.
Also thanks to OFF for sending me the link to the manuals.

 

[maple2]

Having a new issue with the old 40F! It will occasionally start to drive forward/backwards on its own when another function is used. Also the telescoping in/out function will also occasionally engage when another function is used. Anybody have an idea where I should start looking to resolve this?

 

[OFF]

Having a new issue with the old 40F! It will occasionally start to drive forward/backwards on its own when another function is used. Also the telescoping in/out function will also occasionally engage when another function is used. Anybody have an idea where I should start looking to resolve this?

Looking back, I see your machine has the Bertea proportional valves which I didn't get much experience with. (they didn't like Canadian cold, so very few found their way up here).

However, I have a Berta Valve manual.

 

[maple2]

Thank you off. That should be a big help. Did quick back reading on this thread where willie59 mentioned dirty pilot components of the valve can cause the symptoms. Is it possible just to change the hydraulic fluid and new filter to solve this issue or would the pilot have to be taken out and cleaned? What is recommended for the new hydraulic oil for the 40f if this is done? Universal tractor hydraulic fluid?

 

[OFF]

Yes, things are sticking on you in both the Bertea and Racine valve banks. Could very well be dirty or contaminated oil. Good first step.

What we used on them back in the day was a universal SAE 22 hydraulic oil. You don't want to put anything too thick in there. Tractor fluid is usually in the SAE 40 range. There is also an Arctic 15 hydraulic oil we use now. I would recommend that if you use your 40F in winter temperatures.
I have also used Dextron type automatic transmission fluid. What ever you can get for cheaper?