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The JLG 40F Boom Lift Dilemma

dbris

Active Member
Joined
Mar 27, 2010
Messages
32
Location
Los Angeles
Sure does look like the same lump. I'll take another look at it, maybe it's been modified but I'd swear there was no solenoid on it!:beatsme

Well, the lumps match and it has the coil (hidden in 35 years of muck) :eek: It seems to be wired to be on all the time so I need to do a little more research. Other than intermittent left steering, my one remaining problem is why there are 2 solenoids on the hi drive valve. I really appreciate the help that I'm getting from this forum, especially from OFF and ATCO you guys are great!
 

willie59

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Dec 21, 2008
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13,462
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Knoxville TN
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Service Manager
Been years since I've looked at one of those things, but that high drive solenoid is a mystery to me. Not sure why it has two solenoid coils, it doesn't show two on the schematic. But looking at the pic, it looks like an inlet section with a solenoid valve, and a relief section with another solenoid valve. Don't know why they would rig it up like that, but I'd bet they both power up when you select hi-drive. Are you familiar with a valve rigged like that OFF?
 

OFF

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Sep 30, 2009
Messages
1,048
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Alberta, Canada
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HD Mechanic
Been years since I've looked at one of those things, but that high drive solenoid is a mystery to me. Not sure why it has two solenoid coils, it doesn't show two on the schematic. But looking at the pic, it looks like an inlet section with a solenoid valve, and a relief section with another solenoid valve. Don't know why they would rig it up like that, but I'd bet they both power up when you select hi-drive. Are you familiar with a valve rigged like that OFF?

:beatsme

One possible answer is the "two Speed" drive motor option. And I guess the way to tell would be to pull a cover off a drive motor and see what's there is for hoses.
NOT counting the hose to the brake, with a normal single speed drive motor you should see 2 large hoses and 1 small hose (case drain). With the 2 speed motors you'll have 4 - 2 large hoses and 2 small hoses. Again, not counting the brake hose.

I must admit however that I'm a little confused about whether we're talking solenoids or solenoid valves. :eek:
 

willie59

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Dec 21, 2008
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Knoxville TN
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Service Manager
I must admit however that I'm a little confused about whether we're talking solenoids or solenoid valves.

I'm looking at the solenoid valve assy in the first pic of post #231. Thinking it's the hi drive solenoid valve, but it has 2 coils on it. I don't see anything like that on the electrical schematic. That's the valve I was asking if you've seen before.
 

OFF

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I'm looking at the solenoid valve assy in the first pic of post #231. Thinking it's the hi drive solenoid valve, but it has 2 coils on it. I don't see anything like that on the electrical schematic. That's the valve I was asking if you've seen before.

I've never seen that setup on a 40F either. I'm thinking it's a dump valve for the other bang-bangs and a high drive valve. Valves with an angled plug on them like that top one in the picture always contain a pressure relief cartridge and usually associated with a function that has a lock-out. There are no lockouts on a 40F.
In post 225, the second picture shows a three section bang-bang valve bank with a dump. Three sections are not enough to run a 40F. Let's say they are Telescope, Steer, and basket rotate. Where's basket level? In the top picture of post 225 you can see the hoses leaving those 2 valves and heading
behind the bulkhead the bang-bangs are bolted to. I think there could be another bang-bang back there......maybe.....which would explain the extra dump. :beatsme
 

willie59

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LoL, those machines are way back in the cobwebs of my head to remember what components they had on them. :tong

I noticed that relief cartridge in the solenoid on top, very much like the dump valve section you typically see on the bang valve stack of the H models and such. Didn't they make some 40F's that had a manual basket rotate? And therefore wouldn't need a solenoid valve for that function? Can't remember for sure. :)
 

dbris

Active Member
Joined
Mar 27, 2010
Messages
32
Location
Los Angeles
:beatsme

One possible answer is the "two Speed" drive motor option. And I guess the way to tell would be to pull a cover off a drive motor and see what's there is for hoses.
NOT counting the hose to the brake, with a normal single speed drive motor you should see 2 large hoses and 1 small hose (case drain). With the 2 speed motors you'll have 4 - 2 large hoses and 2 small hoses. Again, not counting the brake hose.

I must admit however that I'm a little confused about whether we're talking solenoids or solenoid valves. :eek:

It's the single speed motor, 2 large hoses and 1 drain + brake, and I think we can safely say "solenoid valves".
 

dbris

Active Member
Joined
Mar 27, 2010
Messages
32
Location
Los Angeles
I've never seen that setup on a 40F either. I'm thinking it's a dump valve for the other bang-bangs and a high drive valve. Valves with an angled plug on them like that top one in the picture always contain a pressure relief cartridge and usually associated with a function that has a lock-out. There are no lockouts on a 40F.
In post 225, the second picture shows a three section bang-bang valve bank with a dump. Three sections are not enough to run a 40F. Let's say they are Telescope, Steer, and basket rotate. Where's basket level? In the top picture of post 225 you can see the hoses leaving those 2 valves and heading
behind the bulkhead the bang-bangs are bolted to. I think there could be another bang-bang back there......maybe.....which would explain the extra dump. :beatsme

Of the 3 hoses connected to the valve with the "angled" plug (hi drive), one is from the pump, one to the tank and one to the dump valve for the proportional stack. the 3 proportional valves are drive, lift and swing. The other 3 bang bangs are basket level, telescope and steer. One other note, I think that this machine is a little older than the schematic shows since it's missing some things like the ammeter, horn, clogged filter light and emergency stop.
 

OFF

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Alberta, Canada
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LoL, those machines are way back in the cobwebs of my head to remember what components they had on them. :tong

I noticed that relief cartridge in the solenoid on top, very much like the dump valve section you typically see on the bang valve stack of the H models and such. Didn't they make some 40F's that had a manual basket rotate? And therefore wouldn't need a solenoid valve for that function? Can't remember for sure. :)

I've never seen a manual basket rotate, but you could be right. That would explain the missing valve.

dbris - does your machine have basket rotate?
 
Joined
Apr 12, 2010
Messages
8
Location
bellefonte,pa
Occupation
mechanical/electrical fabricator
hello, i am new to this and i need wiring schematics for the jlg 40f also, did you get the wiring down,if so could you help me out of a bind, my lift ony goes up when you push the buttons on the controls,i was stuck in air a while,i got it runnen and couldn't waite to try it,took 20 min to get down,,same problem,someone played with wiring.thanks,,Adam..
 

dbris

Active Member
Joined
Mar 27, 2010
Messages
32
Location
Los Angeles
hello, i am new to this and i need wiring schematics for the jlg 40f also, did you get the wiring down,if so could you help me out of a bind, my lift ony goes up when you push the buttons on the controls,i was stuck in air a while,i got it runnen and couldn't waite to try it,took 20 min to get down,,same problem,someone played with wiring.thanks,,Adam..
Hi Adam, I'm certainly no expert but I'll send you the parts and service manual that OFF sent to me. There are some folks on this forum that have experience with the 40F and I'm sure that they'll be glad to help. Dave
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,048
Location
Alberta, Canada
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HD Mechanic
hello, i am new to this and i need wiring schematics for the jlg 40f also, did you get the wiring down,if so could you help me out of a bind, my lift ony goes up when you push the buttons on the controls,i was stuck in air a while,i got it runnen and couldn't waite to try it,took 20 min to get down,,same problem,someone played with wiring.thanks,,Adam..


Welcome to the site :)

Is it only the boom up/boom down function that's acting up? Does it work from the ground controls ok? When you get the book from dbris, look through and pick out what brand of controllers & valves you have and let us know. It really helps with nailing down a problem.
 
Joined
Apr 12, 2010
Messages
8
Location
bellefonte,pa
Occupation
mechanical/electrical fabricator
Hey od1, since OFF is taking care of twebbjr and his PWM boards, I've got something for you showing how your PQ controller works the Bertea coils.

Power comes to the controller at the A terminal, then goes to the micro switch (neutral switch on drawing) that's operated by a cam on the side of the controller. When you move the controller in either direction, it operates the switch, which sends power to the C terminal (which goes to the dump valve), and also sends voltage through two resistors to the B and D terminals, and finally to the coil. Since the valve coil has equal postive voltage from either side, and no ground at this point, the coil does not react to move the valve. Back at the controller is the 100 ohm potentiometer which connects between the wires going to B and D terminals. In lever neutral, the pot is centered, making equal resistance to the B and D wires, and the sweep (the arrow coming from the F terminal) inside the pot connects to ground. So you have equal voltage going through the resistors to the coil, and the voltage is being reduced by the resistor in the pot going to ground, everything is balanced. Now, move the controller full stroke to CW rotation. That makes the sweep (arrow) go fully to one side. Now the voltage on B increases because the ground F has moved farther away from it via the pot resistor change, this increases voltage on the B wire going to coil. Likewise, the D wire has a more direct path to ground F because the sweep has moved closer to the D wire and decreased the resistance path. Now you have voltage going to one side of the coil winding and a ground coming back from coil winding which causes valve to shift. ;)



View attachment 49903
can you help me find the jlg 40f lift wiring schematics? thank you...
 
Joined
Apr 12, 2010
Messages
8
Location
bellefonte,pa
Occupation
mechanical/electrical fabricator
thank you all for sending them,i got them,i'm still new to site and didn't check me mail,sorry,thanks again,,,,,,,,
 
Joined
May 31, 2010
Messages
5
Location
cleveland
Occupation
engineer
i finally registered after reading all 18 pages of this post, wow i learned more than i was asking for. i have a jlg 40f works pretty good, just finished building a new fuel tank that looks like the oem, the rust in the bottom the bottom of the tank was over a inch thick and this was after pouring a couple of gallons of hydrocloric acid to clean the tank. so we built a new tank.

had the govenor on the wisconsin engine go bad and the engine free rev'd i wired the throttle in place so we could move it. simple part and a cheap fix also had a problem with water getting into the cylinders via open exhaust pipe, had the starter rebuilt used "southeastern starter and alt in baxley ga. they do good work.

everything works on this unit except the back up emergency/safety controls. all will work when the engine is running, on the ground and in the bucket, but when using the smaller electric back up pump they stop working except for the boom extend in/out. i can not even get the boom to come down when in th eair which should not require much hydraulic pressure from the small pump, the manuel hand valve for bleeding off pressure does work.

ther are 2 wires that have been disconnected, but everything seems to work when the engine is running
i am totally confused

advise
 
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