The JLG 40F Boom Lift Dilemma

[exwestracer]

Oh, and if anyone has the voltage sweep values for PQ controllers, that would really help.
I skipped many of the middle pages, so I'm sorry if I'm asking for a repost...:tong

Merry Christmas

 

[OFF]

Oh, and if anyone has the voltage sweep values for PQ controllers, that would really help.
I skipped many of the middle pages, so I'm sorry if I'm asking for a repost...:tong

Merry Christmas

Welcome exwestracer, check out post #99 on page 7 of this topic. It explains how a PQ controller functions with Bertea valves.

Click on my user name, it give you the option of sending me an email or private message where you can give me an email address to send you a manual set & drawings.

 

[willie59]

Welcome exwestracer, check out post #99 on page 7 of this topic. It explains how a PQ controller functions with Bertea valves.

Click on my user name, it give you the option of sending me an email or private message where you can give me an email address to send you a manual set & drawings.

Page number depends on the size of the monitor of your device, on my computer it's page #3. But you are correct, it's post #99. :drinkup

 

[exwestracer]

Welcome exwestracer, check out post #99 on page 7 of this topic. It explains how a PQ controller functions with Bertea valves.

Click on my user name, it give you the option of sending me an email or private message where you can give me an email address to send you a manual set & drawings.

Already screen shot that post and we are using it for testing! (At first I didn't realize it was for Bertea)
Email sent. THANKS!

 

[exwestracer]

One other quick question:
I'd read earlier in the thread about the possibility of the dump valve poppet spring being weak. On the Bertea valve, is there any spec for how hard the dump valve poppet should be to open manually (removed from valve body)? I can open it with light pressure with a screwdriver on the valve head. We are checking to make sure the solenoid pilot ports are clean. The dump solenoid does appear to be moving the pilot valve.
Thanks again.

 

[exwestracer]

Thanks, OFF. Those manuals and LEGIBLE drawings were very helpful.

We have it nailed down to the Bertea dump valve not closing. (I can see you all sitting there nodding your heads ) We have verified that the solenoid is working and the pilot valve is opening and closing. We have had the poppet valve out, cleaned it, and verified that it moves freely; but it still wont build any pressure in the valve stack. Is that something that can be replaced, or does someone have a fix for it?

Thanks

 

[OFF]

Thanks, OFF. Those manuals and LEGIBLE drawings were very helpful.

We have it nailed down to the Bertea dump valve not closing. (I can see you all sitting there nodding your heads ) We have verified that the solenoid is working and the pilot valve is opening and closing. We have had the poppet valve out, cleaned it, and verified that it moves freely; but it still wont build any pressure in the valve stack. Is that something that can be replaced, or does someone have a fix for it?

Thanks

Glad you got the stuff. Actually the member who started this epic sized topic (OD1) is having exactly the same problem you are with his Bertea equipped 40F. I had very little exposure to Bertea valves, so I haven't been much help to him. Every JLG I worked on "back in the day" was either Racine or Moog or FPS valves. I hope you find the answer, I'll be cheering you on.

Condors used Bertea valves and in the Condors the valves were virtually trouble free. The difference is Condor used a John Deere hydraulic piston pump that only made pressure on demand so it didn't use any dump valves. What ever JLG engineers did to make Bertea valves operate on the gear pumps/dump valves JLG used at the time, didn't work as well.

 

[exwestracer]

Well, we are still about stumped on this. We've had the dump valve and pilot valve completely apart and found some bad o-rings and debris. Replaced the o-rings and cleaned everything out, but we still have no motion out of the Bertea stack. I'm wondering about the bypass line (no. 44 in the picture). Is that the outflow from the dump valve? If so, can I install an "inline" valve to close it off to verify once and for all that the dump is the problem? The schematic shows the flow line from the Hi-drive connecting at that same port, but ours does not seem to be plumbed that way.

Any other ideas on absolutely verifying that the dump is the problem? We've checked everything electrically and there is no signal to the dump solenoid on lift up or down, but swing and drive controls appear to be operating the dump solenoid normally.

Update: Swing, Lift, and Drive are working (by manually closing the valves on the stack), but this is WITHOUT energizing the dump valve solenoid. CONFUSING....

 

[dn29626]

JLG 40 F
I have spent many of the last 48 hours reading this 92 page thread (more like a book).
Including mine, there are more than 75 machines recorded here. I am not counting the many other JLG's mentioned.
Wow at the information.
This is the only thread where so many contributors have been invited to use the same thread, on any site, that I have been a member of. Strangely impressive.

 

[od1]

JLG 40 F
I have spent many of the last 48 hours reading this 92 page thread (more like a book).
Including mine, there are more than 75 machines recorded here. I am not counting the many other JLG's mentioned.
Wow at the information.
This is the only thread where so many contributors have been invited to use the same thread, on any site, that I have been a member of. Strangely impressive.

:beerchug

 

[willie59]

I think even John L Grove would be proud. Not so much that we've compiled all this information on his machine in one thread, but that his machine would still be so prevalent after all these years to compile all this information in a single thread. It seems he built a machine that refuses to die and be carried off to the scrap yard. Hat's off to John L Grove. :drinkup

 

[dn29626]

I looked over my 40F again today after reading this thread.
I am not the original owner, but I have had it for years.
Because many here have posted about their serial number, I looked for mine, did not see it.
I am sure it is there somewhere.
I will post pictures soon, need to understand the how-to-post

 

[BFG]

THank you for your time

Gentlemen, thank you for your time and knowledge, we recently rescued a 40F (we believe) from the weeds and could really use a copy of any paperwork you fine fellers would be willing to send. We are having several functional and control issues we need to systematically diagnose, so having reliable information is absolutely necessary, we have been trying to interoperate from a 40H manual with little success. I have spent hours reading this forum and am glad to find that you are all still in contact to potentially save my rump. thank you in advance!

 

[OFF]

Gentlemen, thank you for your time and knowledge, we recently rescued a 40F (we believe) from the weeds and could really use a copy of any paperwork you fine fellers would be willing to send. We are having several functional and control issues we need to systematically diagnose, so having reliable information is absolutely necessary, we have been trying to interoperate from a 40H manual with little success. I have spent hours reading this forum and am glad to find that you are all still in contact to potentially save my rump. thank you in advance!

Welcome BFG! after reading all this, you know the drill. Send me a PM (private message) with an email address and I'll gladly send you what we have.

 

[OFF]

I think even John L Grove would be proud. Not so much that we've compiled all this information on his machine in one thread, but that his machine would still be so prevalent after all these years to compile all this information in a single thread. It seems he built a machine that refuses to die and be carried off to the scrap yard. Hat's off to John L Grove. :drinkup

Willie, I admit that I am amazed every time another JLG F series comes out of hiding and surfaces on this forum. I have no idea how many they built, but they must all be present and accounted for!

 

[willie59]

I have no idea how many they built, but they must all be present and accounted for!

Naa, there's still at least a half a dozen still out there in hiding, they'll show up here in due course.

 

[bigboy2000]

Hey all, this is my first post and I have to say first I'm really impressed by the amount of community and information around the 40F. I've been scouring the internet for a service manual in PDF for mine (which could certainly use some work). If I understand correctly, OFF seems to have it and has been so gracious to pass it along a few times. Thanks for all the time and love you've put into documenting these old machines - it might just keep mine alive!

 

[bigboy2000]

Oh I forgot to mention that I figured out that mine is a 40F by comparing it to pictures on google images, etc due to the fact that there is no discernible plate with a serial / model number visible on mine. It's been painted at least once, but there's no rivet marks or outline in the places it would be found. So 40F is my best guess, based on what I've seen, and I'm almost 100% sure that's what it is. But if there's another model that's similar I'd love to hear about it.

 

[willie59]

Welcome to HEF bigboy2000. :drinkup

You need to get three posts in to drop the probationary member status, then you can send your email in a private message so we can get the info to you.

 

[willie59]

Oh I forgot to mention that I figured out that mine is a 40F by comparing it to pictures on google images, etc due to the fact that there is no discernible plate with a serial / model number visible on mine. It's been painted at least once, but there's no rivet marks or outline in the places it would be found. So 40F is my best guess, based on what I've seen, and I'm almost 100% sure that's what it is. But if there's another model that's similar I'd love to hear about it.

The ID plate on the 40F was typically in the platform. Not unusual for them to disappear as old as those machines are.