The JLG 40F Boom Lift Dilemma

[ATCOEQUIP]

Originally Posted by arjaytee

I have received it too. Good stuff. Thanks!

Your welcome.

As for your pump, been too long since I've worked on one to remember the brand of pump and specs. I remember it's a 3 stage gear pump, that's about it. I think I would remove it and start looking it over for any identification info and numbers. If nothing else, take it to a hyd/pump shop and see if they can tell what it is.

[tool_king]

ATCOEQUIP
Can you send me the schematics and manual you sent to arjaytee.Please send them to tool_king@hotmail.com .It would be big help to have the information on these.

[ATCOEQUIP]

Originally Posted by tool_king

ATCOEQUIP
Can you send me the schematics and manual you sent to arjaytee.Please send them to tool_king@hotmail.com .It would be big help to have the information on these.

Sure, just give me a little time.

Since your a road tech, I'll also send the schematics for 40F with Bertea valves.

[arjaytee]

Originally Posted by ATCOEQUIP

Your welcome.

As for your pump, been too long since I've worked on one to remember the brand of pump and specs. I remember it's a 3 stage gear pump, that's about it. I think I would remove it and start looking it over for any identification info and numbers. If nothing else, take it to a hyd/pump shop and see if they can tell what it is.

Good memory on the pump, it is a 3-stage unit. I did find some numbers on the mounting flange after power washing it. I'm going to try a google search to see what I get. It looks like pump removal will be necessary. Leaking around the pump input shaft I think.

[ATCOEQUIP]

Originally Posted by arjaytee

Good memory on the pump, it is a 3-stage unit. I did find some numbers on the mounting flange after power washing it. I'm going to try a google search to see what I get. It looks like pump removal will be necessary. Leaking around the pump input shaft I think.

If you have a leak at pump input shaft, you may get lucky and simply need a new seal. Be prepared though, in many cases, the seal is leaking because it has excessive pressure on it from worn pump end plates or shaft bushings. Hope you get it sorted out.

[tool_king]

Thank you Pual for sending over the files.Let me know if you ever need any info I have a lot of stuff im my laptop and in books that I can copy and send.

[ATCOEQUIP]

Your welcome, last PDF of the parts manual on its way.

[TRbond]

I am working on a 40F with only 2 problems I know of so far. (1) boom rotation problem. The boon will turn clockwise but not counterclockwise, I don't think it is in the basket controls. (2) I can't use the ground controls because when I flip the switch to ground controls the engine shuts off. If anyone can email me the wiring diagrams and parts info. I need joysticks, where is the cheapest place to order them?

[ATCOEQUIP]

Welcome to the forum TRbond.

Do you have Racine or Bertea control valves?

[TRbond]

I will have to check the valve type. Can you email me info for both?

[flhayman]

I have used my JLG 40F for some projects, and now it's for sale, since a local guy wanted to get rid of his 4wd lift. The 40F is amazingly solid and well built, to me. As with any low priced machine, there are a few little things to fix, but the new parts are worth close to what i'm asking, $2750 in Florida, with help loading/driving onto truck.
Anyway, one of the things I've been wondering about is why sometimes I have to blip a function, such as platform level, in order to get the swing or lift function to work. The valves for all the proportional functions were replaced with new bang bang valves in a parallel D5 block, (I still have the proportional controls, but there was a leak and nobody in my small town wanted to fix them). The pressure filter was similarly unknown to my NAPA store and my local hydraulic shop, so I put in a generic25 gpm return filter instead. I have thought that there might be some back pressure that is tending to hold the holding valves, which is relieved when I blip another function on the same dump valve. Or is it the dump valve leaking?
You guys really know your stuff, and I'm just a farm handyman. I have an expensive copy of the JLG manual, but it leaves a lot out, and like you said, has some very challenging small print in the electrical schematic!
I have learned a lot from reading here, and want to thank those knowledgeable folks who contribute their time to this publicly accessible forum. The internet was originally conceived for this kind of research, I think, although they may not have envisioned heavy equipment at first!