L35 Husco hydro's

[Nicksacco]

Hmmm, well it shouldn't just dribble out thats for sure!
It should come out with some force.
The rated GPM is about 17 gallons/minute for the FEL - TL720.

Hopefully you'll get your gauge soon for better diagnosis

 

[PoTreeBoy]

Yes the coupling pictured in the circle. I replaced the coupling, two bearings, and the cap. No leaks because the transmission and steering are working. I suppose it could be something inside the pump itself. Once I get pressure gauge then I can test in certain areas and see if we build pressure. I am not versed in hydraulic systems so I am learning as I go. No i did not take the pump apart but wishing I would have. How would I know if it is the pump not working properly?

If mine had this issue, I'd take the coupler off the hose coming from the FEL valve shown below.

This is the power beyond hose.

Take the coupler off and stick the end of the hose in the filler port. (Clean things up first so dirt doesn't fall in.) Start the tractor at an idle. With the joystick neutral, there should be flow, 11 gpm at full throttle. (A garden hose is about 3-5 gpm, so at full throttle you'll make a big mess.) If you move the joystick to move the bucket or lift arms, the flow should stop.

Edit. Yours will look a little different since my hose loops through my backhoe and I don't think your hoe is installed, so your hose connects to a fitting which would be in the right-center of my photo.

 

[TheOldHokie]

If mine had this issue, I'd take the coupler off the hose coming from the FEL valve shown below.
View attachment 113160
This is the power beyond hose.

Take the coupler off and stick the end of the hose in the filler port. (Clean things up first so dirt doesn't fall in.) Start the tractor at an idle. With the joystick neutral, there should be flow, 11 gpm at full throttle. (A garden hose is about 3-5 gpm, so at full throttle you'll make a big mess.) If you move the joystick to move the bucket or lift arms, the flow should stop.

Edit. Yours will look a little different since my hose loops through my backhoe and I don't think your hoe is installed, so your hose connects to a fitting which would be in the right-center of my photo.

I am lazy this morning and have not looked at the manuals. Is there a pressure relief upstream of that coupler? If so he can just hook his gauge to that hose and test pressure at the same time he is checking for flow. As you know if there is not a relief in the circuit he can't do that without deadheading the pump. He needs to be careful testing pressure.

Dan

 

[Nicksacco]

There is, Dan.
And @jt2hunt mentioned he's looked at it thinking it might have been problematic.

 

[TheOldHokie]

There is, Dan.
And @jt2hunt mentioned he's looked at it thinking it might have been problematic.





View attachment 113163

That looks like it's in the 3pt lift circuit. Isn't that downstream of the hoe?

Dan

 

[Nicksacco]

Dan mentions being careful when checking pressure. Do you have the shop manual?
Here are some pages:

 

[Nicksacco]

That looks like it's in the 3pt lift circuit. Isn't that downstream of the hoe?

Dan

Check this out:

 

[TheOldHokie]

Check this out:

View attachment 113169

According to that schematic DV1 is a directional valve with one inlet and one outlet port. Really - how does that work? There is no indication of a relief in the loader valve so maybe but it's not at all clear to me from that drawing.

Dan

 

[Nicksacco]

Yes it's kinda weird.
Looking at the diagram below:

1) Pump delivers high pressure oil thru 010, 080 (to "A") 090
2) oil goes thru 100 and 110 (bolted together)
3) Diverter 200 if turned to FEL directs oil thru 180 to FEL Controls up front
4) FEL control (not shown) Power Beyond goes back to input on Backhoe (not shown)

It appears that the BH-3PTH control valve on the right side of the cylinder controls flow to BH or 3PTH
The Relief Valve "R" is monitoring pressure in FEL, or 3PTH depending upon which way the control valve is selected.

This is a guess, however Kubota must've designed this machine to be able to use either or both FEL and BH (not at same time) and runs the high pressure oil thru the same relief valve "R".

I suppose you could use both BH and FEL at the same time with two operators working the controls but why would you?

 

[TheOldHokie]

Yes it's kinda weird.
Looking at the diagram below:

1) Pump delivers high pressure oil thru 010, 080 (to "A") 090
2) oil goes thru 100 and 110 (bolted together)
3) Diverter 200 if turned to FEL directs oil thru 180 to FEL Controls up front
4) FEL control (not shown) Power Beyond goes back to input on Backhoe (not shown)

It appears that the BH-3PTH control valve on the right side of the cylinder controls flow to BH or 3PTH
The Relief Valve "R" is monitoring pressure in FEL, or 3PTH depending upon which way the control valve is selected.

This is a guess, however Kubota must've designed this machine to be able to use either or both FEL and BH (not at same time) and runs the high pressure oil thru the same relief valve "R".

I suppose you could use both BH and FEL at the same time with two operators working the controls but why would you?


View attachment 113174

Thats a little clearer. The geometry of that crazy DV1 diverter block plumbing is what had me confused. The relief is effectively teed off the supply coming in on block 100. The diverter valve in block 200 routes the other side of that tee to either 3pt via second port in block 100 or loader pipe via block 200.

When loader is selected pump flow continues thru loader valve to BH inlet, thru BH valve and then back to DV2 where it is routed to tank in the BH position or 3pt inlet in the 3pt position.

Loader and BH valve are in series with either 3pt or tank at the end of the chain.

Rube Goldberg would be proud.

Dan

 

[PoTreeBoy]

Thats a little clearer. The geometry of that crazy DV1 diverter block plumbing is what had me confused. The relief is effectively teed off the supply coming in on block 100. The diverter valve in block 200 routes the other side of that tee to either 3pt via second port in block 100 or loader pipe via block 200.

When loader is selected pump flow continues thru loader valve to BH inlet, thru BH valve and then back to DV2 where it is routed to tank in the BH position or 3pt inlet in the 3pt position.

Loader and BH valve are in series with either 3pt or tank at the end of the chain.

Rube Goldberg would be proud.

Dan

The L35's hydraulic is unique. Here's the full schematic, the one I posted earlier was from the loader section. The discharge from the front pump goes to the relief valve located in the lift cylinder block, then normally back to the loader valve (which has no relief valve), the backhoe, and then the 3pt valve (or diverted to tank if hoe is installed). Lots of plumbing. The suction side is interesting, too.

 

[TheOldHokie]

The L35's hydraulic is unique. Here's the full schematic, the one I posted earlier was from the loader section. The discharge from the front pump goes to the relief valve located in the lift cylinder block, then normally back to the loader valve (which has no relief valve), the backhoe, and then the 3pt valve (or diverted to tank if hoe is installed). Lots of plumbing. The suction side is interesting, too.
View attachment 113176

The circuit is not particularly unique but the plumbing with those two stacked blocks at the 3pt housing certainly is. The loader selector valve (aka DV1) is not a three way diverter- it's a shut off. Once I figured that out the rest fell into place. Guess I am a slow learner

Dan

 

[PoTreeBoy]

The circuit is not particularly unique but the plumbing with those two stacked blocks at the 3pt housing certainly is. The loader selector valve (aka DV1) is not a three way diverter- it's a shut off. Once I figured that out the rest fell into place. Guess I am a slow learner

Dan

I'm pretty sure DV1 is not mentioned in the Op Manual, and maybe not in the WSM. Since the loader is an integral part of the tractor, DV1 has no real use, as far as I can tell. But if it were to get shifted inadvertently it could cause a troubleshooting issue.

 

[TheOldHokie]

I'm pretty sure DV1 is not mentioned in the Op Manual, and maybe not in the WSM. Since the loader is an integral part of the tractor, DV1 has no real use, as far as I can tell. But if it were to get shifted inadvertently it could cause a troubleshooting issue.

It is shown in your schematic. The only use I can see for it would be if the loader valve were removed and/or disconnected from the pump. The loader circuit looks like an afterthought but the other diverter is an integral part of the 3pt.....

Dan

 

[jt2hunt]

I will not be able to work on my tractor until this weekend. I did get my pressure gauge.

 

[jt2hunt]

If mine had this issue, I'd take the coupler off the hose coming from the FEL valve shown below.
View attachment 113160
This is the power beyond hose.

Take the coupler off and stick the end of the hose in the filler port. (Clean things up first so dirt doesn't fall in.) Start the tractor at an idle. With the joystick neutral, there should be flow, 11 gpm at full throttle. (A garden hose is about 3-5 gpm, so at full throttle you'll make a big mess.) If you move the joystick to move the bucket or lift arms, the flow should stop.

Edit. Yours will look a little different since my hose loops through my backhoe and I don't think your hoe is installed, so your hose connects to a fitting which would be in the right-center of my photo.

I did what you mentioned above. I do have flow, not sure how much. When i throttle up, the flow increases but not enough to cause a mess as it is directed into the fill port. I suppose I could get a gallon bucket and time how long it takes to fill.

I remember something that may help. When I started to diagnose the issue and looking at the arm that selects 3pt or backhoe option and went to push it in and out I noticed is seemed to have rotated to far under the seat. I remember hearing a knock noise when i lost hydraulic power. I was able to move the selector in and out and did not open too far in the position that i noticed.

Is it possible that under the seat something snapped? There is a control valve distibutor that has two poppets and springs inside? I am going to fill a gallon bucket and time it to determine how many gpm's.
I pulled the pressure relief valve. I do not notice any difference in the amount of pressure i have to apply to push in the valve, regardless of how far in or out the setting is on the valve.
Will report back.

 

[jt2hunt]

Latest update. I reinstalled the pressure relief valve. I then screwed it down as far as possible. I measured the flow and I am getting a gallon per 20 sec. 3 gpm. This is at low idle. I put the coupler back together and started the tractor.

3 pt hitch moved and fel is working. Not sure how long it will work, but let's see. I did aggressively move the 3 pt and backhoe selector in and out a few times.

I think it was tightening down on the relief valve as hard as possible.

As of now, I am not 100% sure of the issue. Working now.

 

[TheOldHokie]

I did what you mentioned above. I do have flow, not sure how much. When i throttle up, the flow increases but not enough to cause a mess as it is directed into the fill port. I suppose I could get a gallon bucket and time how long it takes to fill.

I remember something that may help. When I started to diagnose the issue and looking at the arm that selects 3pt or backhoe option and went to push it in and out I noticed is seemed to have rotated to far under the seat. I remember hearing a knock noise when i lost hydraulic power. I was able to move the selector in and out and did not open too far in the position that i noticed.

Is it possible that under the seat something snapped? There is a control valve distibutor that has two poppets and springs inside? I am going to fill a gallon bucket and time it to determine how many gpm's.
I pulled the pressure relief valve. I do not notice any difference in the amount of pressure i have to apply to push in the valve, regardless of how far in or out the setting is on the valve.
Will report back.

Latest update. I reinstalled the pressure relief valve. I then screwed it down as far as possible. I measured the flow and I am getting a gallon per 20 sec. 3 gpm. This is at low idle. I put the coupler back together and started the tractor.

3 pt hitch moved and fel is working. Not sure how long it will work, but let's see. I did aggressively move the 3 pt and backhoe selector in and out a few times.

I think it was tightening down on the relief valve as hard as possible.

As of now, I am not 100% sure of the issue. Working now.

I doubt the relief valve had anything to do with it. I think you better test the setting.

Dan

Dan

 

[PoTreeBoy]

Latest update. I reinstalled the pressure relief valve. I then screwed it down as far as possible. I measured the flow and I am getting a gallon per 20 sec. 3 gpm. This is at low idle. I put the coupler back together and started the tractor.

3 pt hitch moved and fel is working. Not sure how long it will work, but let's see. I did aggressively move the 3 pt and backhoe selector in and out a few times.

I think it was tightening down on the relief valve as hard as possible.

As of now, I am not 100% sure of the issue. Working now.

I agree with TheOldHokie, the relief valve was probably not the problem and should be reset to the proper pressure.

That selector valve, when in the backhoe position, dumps the power beyond flow to tank, bypassing the 3ph. Mine stays in that position, since I keep the hoe mounted. It could be the source of your problem
1. If it's not fully one way or the other, it could be blocking the flow partially or fully. I don't know if this is possible.
2. When it's in the 3ph position, the lift control valve comes into play (of course). That control has a feedback linkage which, if maladjusted, can call for flow when the lift is fully up. This deadheads the power beyond flow and prevents the FEL from functioning. The easy fix is to lower the 3ph control lever off full up. The correct fix is to adjust the linkage properly.

Edit: forget option 1. The valve is on or off. Partially closed would affect the 3ph but not the loader.