M8540 lift arms won't fully lower

RichInTN

New member

Equipment
M8540, BX2200, BX2680, DM1024, WG6
Sep 27, 2013
17
1
3
Middle Tennessee
I had a thread in Tractor Operating, however now it seems more likely it is a service/repair issue rather than operator error.

2009 M8540, No cab, lift assist cylinders.

No attachments on the 3pt.

The position control has virtually no effect (it will raise the arms ever so slightly when pulled all the way back, if the draft control is all the way back).

The draft control all the way back lowers the lift arms about 12" (from about 36" off the ground to about 24"). At about 1/4 the way forward the arms are fully raised (36" off the ground). Any further forward and I can hear the change in the sound of the tractor. At full forward on the draft control there is a significant difference in the sound of the tractor but no change in the lift arm position.

The linkages all appear to be good, no bends or binding.

Fluid level is correct.

I marked the shaft the position control moves, it moves about 1/4" (I'd say somewhere between 20 and 30 degrees) from full forward to fully back.

I sprayed with the tractor about 2 months ago and the 3pt had no problem going to the ground or fully up.

I am applying weight (about 200lbs) to the lift arms and they are definitely not going any lower. I can see on the lift assist cylinders that the cylinders clearly work working farther than they are now.

I have tried the lower rate control all the way clockwise, counterclockwise and in the middle.

I was hoping I was missing something obvious, however at this point it doesn't appear so.

Any advice, suggestions or input is greatly appreciated.

If pictures will help let me know and I'll try to post what is needed.

Rich
 

Bulldog

Well-known member

Equipment
M 9000 DTC, L 3000 DT
Mar 30, 2010
5,440
73
48
Rocky Face, Georgia
Just to get it out there, is there any way the lift assist cylinder could have a air lock and is keeping the arms from dropping? Just to eliminate would it be possible to crack the supply line loose and bleed the cylinder?

I'm running out of ideas myself so this is just a shot in the dark.
 

RichInTN

New member

Equipment
M8540, BX2200, BX2680, DM1024, WG6
Sep 27, 2013
17
1
3
Middle Tennessee
No air in the cylinders or lines.

If I disconnect the Position Feedback linkage I can lower the arms all the way to the ground, but they won't raise back unless I push the linkage forward.

Disconnecting the draft feedback linkage and moving it does not affect anything.

Called the dealer they are at least two weeks behind... back to me trying to figure it out.
 

RichInTN

New member

Equipment
M8540, BX2200, BX2680, DM1024, WG6
Sep 27, 2013
17
1
3
Middle Tennessee
Found the problem and it is resolved!

Having a parts diagram to look at saved the day.

The Position Control by the seat moves a linkage that moves a shaft that moves a linkage arm. This arm has a tab that will push the actual position control lever that goes in to the hydraulics housing. The tab will push the control lever up, however the lever is free to move higher (but not lower). When my Position Control by the seat was lowered the actual lever that goes in to the housing was stuck and not lowering back to meet it. After judicious cleaning and a lot of penetrating oil and manual movement it freed up. It has now been cleaned one final time and lubricated. All is working well.

Essentially it was the equivalent of the Position Control lever by the seat being pulled up (towards the back of the tractor) all the time.

I'll see if I can get some scans of the diagrams and post a follow up with pictures as I am fairly sure my description was hard to follow.

Thanks everyone for all the input.

Rich
 

arobint

New member

Equipment
M7040, M4700
Mar 17, 2021
7
0
1
Quebec, Canada
Found the problem and it is resolved!

Having a parts diagram to look at saved the day.

The Position Control by the seat moves a linkage that moves a shaft that moves a linkage arm. This arm has a tab that will push the actual position control lever that goes in to the hydraulics housing. The tab will push the control lever up, however the lever is free to move higher (but not lower). When my Position Control by the seat was lowered the actual lever that goes in to the housing was stuck and not lowering back to meet it. After judicious cleaning and a lot of penetrating oil and manual movement it freed up. It has now been cleaned one final time and lubricated. All is working well.

Essentially it was the equivalent of the Position Control lever by the seat being pulled up (towards the back of the tractor) all the time.

I'll see if I can get some scans of the diagrams and post a follow up with pictures as I am fairly sure my description was hard to follow.

Thanks everyone for all the input.

Rich
Hi Rich,

I am having EXACTLY the same issue with an M7040. The dealer sent a tech today who spent 4 hours here and only slightly improved the situation. Any chance you could send some pics of what you did to point me in the right direction? Thanks!