B2650HSD Hydraulic Issue

[AnotherOldGuy]

I have 281 hours on my B2650 and it has worked wonderfully for several years of use, mostly during spring, summer and fall, on my small acreage. The last time I used the PTO and 3 point lift was in November of last year when I tilled the garden for winter.

Two days ago, I discovered that I can't move either PTO lever and the 3 point lift arms have only two positions, full up if the lever is at the top of it's travel or full down if the lever is in any other position. It works this way with or without an implement attached to them. Additionally, when the arms reach the top of their travel and the lever is at the top, the engine sound is still like the hydraulic pump is working hard. I found that moving the lever down just a little until the engine RPM picks up will the lift arms stay in the up position. I can drive the tractor, shift the transmission, operate the FEL, use the top and tilt hydraulics running off the Beyond Power port and the power steering works.

I checked the transmission oil level and it was at the very bottom of the dipstick, so I added more until it was at the top mark. Doing this didn't change the behavior of either the PTO levers or the 3 point. I've spent several hours reading and researching the issue to see if anyone else has experienced this, but haven't found any that matched my situation.

I've looked at the levers and top of travel limiter linkages, but nothing stands out like a broken, bent or disconnected link. I replaced the HST filter and drained and refilled with new hydraulic fluid. I started the tractor and exercised all the hydraulic cylinders, but still no change.

I'm not an expert tractor mechanic, but not a total neophyte either. Before buying my Kubota, I tore down my old Yanmar 187D and replaced a cracked transmission case after purchasing a new case and the service and repair manual. I got a good look at the inner workings of an HST and 3 point hitch hydraulics. I was able to complete the work and used my Yanmar for several more years before giving it to a friend who still uses it.

I know that there is a tremendous amout of knowledge and experience here. Any insight into my issue would be greatly appreciated.

 

[TheOldHokie]

I have 281 hours on my B2650 and it has worked wonderfully for several years of use, mostly during spring, summer and fall, on my small acreage. The last time I used the PTO and 3 point lift was in November of last year when I tilled the garden for winter.

Two days ago, I discovered that I can't move either PTO lever and the 3 point lift arms have only two positions, full up if the lever is at the top of it's travel or full down if the lever is in any other position. It works this way with or without an implement attached to them. Additionally, when the arms reach the top of their travel and the lever is at the top, the engine sound is still like the hydraulic pump is working hard. I found that moving the lever down just a little until the engine RPM picks up will the lift arms stay in the up position. I can drive the tractor, shift the transmission, operate the FEL, use the top and tilt hydraulics running off the Beyond Power port and the power steering works.

I checked the transmission oil level and it was at the very bottom of the dipstick, so I added more until it was at the top mark. Doing this didn't change the behavior of either the PTO levers or the 3 point. I've spent several hours reading and researching the issue to see if anyone else has experienced this, but haven't found any that matched my situation.

I've looked at the levers and top of travel limiter linkages, but nothing stands out like a broken, bent or disconnected link. I replaced the HST filter and drained and refilled with new hydraulic fluid. I started the tractor and exercised all the hydraulic cylinders, but still no change.

I'm not an expert tractor mechanic, but not a total neophyte either. Before buying my Kubota, I tore down my old Yanmar 187D and replaced a cracked transmission case after purchasing a new case and the service and repair manual. I got a good look at the inner workings of an HST and 3 point hitch hydraulics. I was able to complete the work and used my Yanmar for several more years before giving it to a friend who still uses it.

I know that there is a tremendous amout of knowledge and experience here. Any insight into my issue would be greatly appreciated.

I would guess something is wrong with the feedback linkage - either externally or internally.

Dan

 

[North Idaho Wolfman]

Have you checked this linkage for the three point issue.

 

[AnotherOldGuy]

The 3 point system feedback linkage isn't damaged and is still set exactly where it was when I picked up the new tractor from the dealer.

I purchased the Kubota Work Shop Manual and have been reviewing everything it has on the Hydraulics, PTO and 3 point systems. I haven't figured out if my two issues are related, but suspect they are since they don't appear to be mechanically linked, but both operate through the hydraulic system and stopped working at the same time.

I took the seat, rear wheels and various guards/brackets off today to open up the view of all the HST, PTO and 3 point linkages. I washed it all off good, then dried with pressurized air. All linkages are as shown in the manual with no missing retention pins or nuts. Nothing is loose, bent, broken or visibly out of adjustment.

I closed and re-opened the 3 point lowering speed knob to where I had it set. With the lower links and the 3 point control lever in the raised position and the engine off, I pushed the control lever about 1/2 way down. The lower links quickly moved to the bottom of their travel and I could hear the hydraulic fluid being pushed out of the 3 point cylinder. I could manually lift the lower links to the top with no noticeable hydraulic resistance. When I let go of the lower links, they dropped down instantly. I did discover that I can move the PTO selection lever easily between both, mid only or rear only positions. However, no matter what position it's in, the arm on the PTO valve is rigid and doesn't move, even when I disengage the PTO engagement lock and tried firmly pushing the lever down.

I guess my next step is to remove the PTO valve from the top of the HST and keep searching the web.

 

[TheOldHokie]

The 3 point system feedback linkage isn't damaged and is still set exactly where it was when I picked up the new tractor from the dealer.

I purchased the Kubota Work Shop Manual and have been reviewing everything it has on the Hydraulics, PTO and 3 point systems. I haven't figured out if my two issues are related, but suspect they are since they don't appear to be mechanically linked, but both operate through the hydraulic system and stopped working at the same time.

I took the seat, rear wheels and various guards/brackets off today to open up the view of all the HST, PTO and 3 point linkages. I washed it all off good, then dried with pressurized air. All linkages are as shown in the manual with no missing retention pins or nuts. Nothing is loose, bent, broken or visibly out of adjustment.

I closed and re-opened the 3 point lowering speed knob to where I had it set. With the lower links and the 3 point control lever in the raised position and the engine off, I pushed the control lever about 1/2 way down. The lower links quickly moved to the bottom of their travel and I could hear the hydraulic fluid being pushed out of the 3 point cylinder. I could manually lift the lower links to the top with no noticeable hydraulic resistance. When I let go of the lower links, they dropped down instantly. I did discover that I can move the PTO selection lever easily between both, mid only or rear only positions. However, no matter what position it's in, the arm on the PTO valve is rigid and doesn't move, even when I disengage the PTO engagement lock and tried firmly pushing the lever down.

I guess my next step is to remove the PTO valve from the top of the HST and keep searching the web.

I was with you and everything sounded normal right up to you started talking about the PTO valve. What problem are we trying to fix? Position control operation or something else?

Dan

 

[North Idaho Wolfman]

The 3 point system feedback linkage isn't damaged and is still set exactly where it was when I picked up the new tractor from the dealer.

I purchased the Kubota Work Shop Manual and have been reviewing everything it has on the Hydraulics, PTO and 3 point systems. I haven't figured out if my two issues are related, but suspect they are since they don't appear to be mechanically linked, but both operate through the hydraulic system and stopped working at the same time.

I took the seat, rear wheels and various guards/brackets off today to open up the view of all the HST, PTO and 3 point linkages. I washed it all off good, then dried with pressurized air. All linkages are as shown in the manual with no missing retention pins or nuts. Nothing is loose, bent, broken or visibly out of adjustment.

I closed and re-opened the 3 point lowering speed knob to where I had it set. With the lower links and the 3 point control lever in the raised position and the engine off, I pushed the control lever about 1/2 way down. The lower links quickly moved to the bottom of their travel and I could hear the hydraulic fluid being pushed out of the 3 point cylinder. I could manually lift the lower links to the top with no noticeable hydraulic resistance. When I let go of the lower links, they dropped down instantly. I did discover that I can move the PTO selection lever easily between both, mid only or rear only positions. However, no matter what position it's in, the arm on the PTO valve is rigid and doesn't move, even when I disengage the PTO engagement lock and tried firmly pushing the lever down.

I guess my next step is to remove the PTO valve from the top of the HST and keep searching the web.

Ok you've lost me too on several points???

The three point has no down force so if you lower the arms hydraulically, then yes you can pick them up and they will just drop , that's normal.

The PTO engagement and selection has Zero to do with the three point operation.
What is the PTO engagement lock??

 

[AnotherOldGuy]

Clearly, I haven't done a good job explaining. I'll answer the questions posed in order.

I have 2 issues, 1) I can't engage the PTO and, 2) the 3 point position adjustment isn't working correctly.

I understand that the 3 point has no downward force from hydraulic pressure because it's a single action hydraulic cylinder. Sorry about the misunderstanding with "I could manually lift the lower links to the top with no noticeable hydraulic resistance." I can only plead old age and a brain fart. I was just trying to explain everything that I've tried so far to isolate and/or diagnose the issues.

I agree the issues shouldn't be related. I just suspected that they might be only because they are hydraulics related and located phyically together. From studying the repair manual, I now see that they are independent.

By "PTO engagement lock", I was trying to explain that you can't just push the lever straight down like the 3 point position lever. You have to pull the lever sideways in order to slide it past the stop, then push it down gradually to engage the PTO clutch.

I partially resolved the PTO engagement issue. The application of penetrating oil while continuing to work the lever back and forth finally got the valve arm freed up. The arm on the PTO valve had stuck to the valve body due to corrosion. My bad for not being more diligent about lubing the levers and linkages more often. Now both PTO levers work better and with much less effort than I can remember.

Now my PTO issue has changed. Once I got the PTO levers working as they should, I started the engine and tried to engage the PTO. The engine immediately stalled. Restarted the engine and let it warm up a bit before trying to engage the PTO again, but it immediately stalled the engine again. Started the engine again and tried to move the PTO selecter lever, engine immediately stalled. Argghh !

 

[North Idaho Wolfman]

Ok, for the PTO issue at hand.
It sounds like it's possible the PTO selector or engagement linkage got bent or out of adjustment and is sticking between on and off, or high / low.

 

[Russell King]

Do you have anything connected to the output of the PTO? Do you also have a Mid PTO? I doubt it but if you do remove that implement. What you describe sounds like the engine is stalling due to load on the output side of the system, like an implement that has seized up.

If there is a cover on the tractor’s PTO stub shaft please remove it just to eliminate any interference it could be causing just to eliminate that possibility.

If there is nothing attached to the PTO shaft at the rear or to the Mid PTO shaft then with the tractor NOT running and the key in your pocket try to rotate the tractor PTO shaft by hand in both directions. It should rotate in one direction as I understand it.

Did this happen all of a sudden or over time? Was the tractor sitting idle for some time between November and now?

For the hydraulic problem it might be better to start a separate thread? But please answer the same question on how it occurred in time.

Describe more about what does not happen when you try to adjust your 3PH? I assume you are referring to position control of the arms, not some overall adjustment of the 3PH to adjust height or squeals.

 

[Dustball]

Now my PTO issue has changed. Once I got the PTO levers working as they should, I started the engine and tried to engage the PTO. The engine immediately stalled. Restarted the engine and let it warm up a bit before trying to engage the PTO again, but it immediately stalled the engine again. Started the engine again and tried to move the PTO selecter lever, engine immediately stalled. Argghh !

I wonder if your seat switch isn't working.

For condition 5, you'd be able to start the engine with the seat switch off if the PTO is disengaged and the HST pedal is in neutral.
For condition 6, everything is the same except that when the PTO is engaged, it would shut the engine off.

You can test this theory by having everything the same except having the parking brake engaged before engaging the PTO.

 

[AnotherOldGuy]

Dustball, you are correct that it was the seat switch, but not because it wasn't working. Operator error when I took the seat and all of the support pieces off to get at the PTO valve. Of couse, I had to disconnect the seat switch. Once again, old age and brain farts ! Connected the seat switch, started the engine, moved the seat switch to the occupied position and engaged the PTO. Engine continues running and PTO shaft is turning normally again.

Thanks to all who tried to help.

I'll start another thread for the 3 point issue.