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JLG 60H no function from dump valve #2

koalamotorsport

Well-Known Member
Joined
Aug 7, 2012
Messages
48
Location
Cleveland OH
Hi Guys.
This antique was working fine when I parked it before winter.

I have no basket level/rotate, no boom in/out and no steering. All four functions are controlled via dump valve #2 and all are controlled purely from the basket with the exception of boom in/out, which can also be controlled from the ground.

The boom in/out does not work from the ground or basket. Swing, boom up/down and drive all work from ground or basket. They are all functions via dump valve #1.

When selecting any of the functions, the motor bogs slightly, as though it has load, but the functions do not work.

I had previously hand an intermittent problem with these functions which I tracked to a loose ground at the dump valve itself. This is not the case now. When that happened, there was no noticeable load on the engine, unlike now.

I have all the wiring diagrams and cannot find anything wrong in control circuits, although deciphering the relays is virtually impossible as they don't show relay diagrams, only connection points.

When the selector switch is set to ground, both dump valve solenoids 1 and 2 are energized. Selecting to basket de-energizes both. I'm working alone and can't 100% confirm that they are being energized when operating basket controls, but by using a "record" function on my multimeter, it seems to be that they are.

My primary question here is does anyone know if the dump valves need to be energized, or de-energized, in order for the function to work. In other words, do the dump valves power open or power closed, and are the functions operational when they are open or closed?

Thanks
 

Geoff Lott

Member
Joined
Oct 19, 2018
Messages
23
Location
Mississippi
Pull correlating valve out of function manifold...they have a problem with blowing the snapring and coming apart...you’ll know it when you see it..issue NO FUNCTIONS
 

Geoff Lott

Member
Joined
Oct 19, 2018
Messages
23
Location
Mississippi
Look up manuals on JLG website and go to the parts manual for it and find dump valve location I believe it’s on the right side of the manifold and pull valve out.. I believe there two valves correlating to it...and you’ll know which one it is...JLG had a campaign on them at one point because it happens so frequently..you got a serial 0300????
 
Last edited:

koalamotorsport

Well-Known Member
Joined
Aug 7, 2012
Messages
48
Location
Cleveland OH
Never got an answer to my actual question in this post, but I finally found time to play today.

Based on Geoff's comment, I went looking for (and never found) the correlating valves.

As both dump valves are powered up with the engine running, I decided to disconnect the solenoid for dump valve #2 and see if functions were restored. They were not. I decided to remove the solenoid from from dump valve #2 to see if it was reacting to being powered up. The magnetic solenoid was activating, but I could see no visual indication of the piston moving (assembly removed from dump valve). An adjustment with a precision tappet stick released the stuck piston, re-assembled and system is functioning correctly.

As a result of the repair, my original question is answered. The dump valves are powered open, dumping pressure, and power is disconnected to close them when the function is activated.

Now to fix the leak in the Racine valve assembly...... A broken bolt holding one of the valve blocks.
 
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