jlg 40ha drive problems

[dscont]

Well fired up the machine, i already have the brakes released , moved the plastic lever on the servo and machine did not move ? You have been a great help this far thank you. now what do you think? All the other hydraulics work fine booom controls, steering everything else just no drive. Is this a double pump or something similar? Is the drive pump seperate from the control pump? Thnaks again for the help.

[willie59]

Well, I think it's time to send it to a pump shop. It could simply be a problem with the servo, could be a problem with the drive pump as well, I'd let an experienced person check it out and repair it if necessary. Call Ron at Fluid Power International and tell him you have a Sunstrand bi-directional pump from a JLG that needs repair, I've sent a good pile of pumps to him over the years with good results, they even cover the cost of return shipping.

http://www.fpihydraulics.com/index.html

There is actually three pumps on your machine. The bi-directional drive pump is connected to the flywheel housing. It's not capable of keeping itself filled with oil so it has a charge pump mounted on the rear of it to feed oil to the drive pump. Looking from the outside, these look like a single unit, but it's actually two pumps, both part of the drive circuit only. The third pump is the work equipment pump for all other hyd functions, it's a gear pump fitted to the rear of the charge pump on main drive pump unit.

[GROUNDWRK]

I have a JLG 40 FR in my shop with a veriety of issues. Looking for wiring and hydraulic diagrams,

[GROUNDWRK]

I understand I have to make 3 posts in order for you guys to send me any files. One problem I'm having is that sometimes when I switch from "Ground Controls " to "Boom Controls" the engine wants to shut off.

[GROUNDWRK]

The FLG 40 FR moves real slow but engine doesnt seem to be laboring, appears to be a hydraulic issue, so week it barely crawled over the concrete lip into the garage. And when you first try to move it the one drive wheel seems like its locking up. I also need some help with the engine high speed throttle solenoid. This is the first time I've worked around one of these, I'm not even sure what function activates the high engine speed solenoid.

[OFF]

Manuals on the way Groundwrk. Welcome

[GROUNDWRK]

Thank You , OFF . As im sure you know, they will be a big help and I didn't know where else I would be able to find them. Its a great thing there are sites like this and folks like you that take the time to help!

[OFF]

Thank You , OFF . As im sure you know, they will be a big help and I didn't know where else I would be able to find them. Its a great thing there are sites like this and folks like you that take the time to help!

Groundwrk - I still need you to message me with your email address so I can send you the manual PDF's. I can't send attachments from on the on-board email system inside the forum.

[GROUNDWRK]

Sorry OFF, I didn't realize,new to this forum stuff. my email is groundworkdesign@verizon.net

[OFF]

Got it groundwrk. Thanks

You may want to edit your email address out of the above post.

I'll get you those manuals very shortly

[GROUNDWRK]

Thanks, I can't seem to edit, no icon, must not have that privelage yet!

[dscont]

Finally got the pump off it is completely scared up. But the oil seems to be perfectly clean . I guess i will drain the oil , flush the system, change filters and then put the rebuilt pump back on . Anything i am missing or should be looking for?

[VoodooMojo]

Well fired up the machine, i already have the brakes released , moved the plastic lever on the servo and machine did not move ? You have been a great help this far thank you. now what do you think? All the other hydraulics work fine booom controls, steering everything else just no drive. Is this a double pump or something similar? Is the drive pump seperate from the control pump? Thnaks again for the help.

Be sure as willie said, to electrically release the brakes by jumpering the brake solenoid with 12v + and ground.
Many people believe they are releasing the brakes by reversing the plate on the drive hub. This does not release the brake but simply pushes the sun gear out of the planetary gearing.
It will definitely not drive if this is the case.

[dscont]

Good news after 2 years of piddiling around with it finally installed new pump and everything works great. Thanks for all the help.

[willie59]

Good to hear you got it sorted out dscont, thanks for the update.