Newbie with an L35

TheOldHokie

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OK You can do the same thing by teeing into the PB at the loader valve. Then disconnect the quick disconnects on the hoses that connect to the backhoe. There are check valves in those disconnects, so this will have the same effect as capping the tee on your test gauge. See what pressure you get, don't run it too long.

Note to @TheOldHokie: the L35 loader valve doesn't have a relief valve. The system relief is back near the lift cylinder, I think, in the line before it gets to the loader valve.
If thats the case the main system relief becomes a potential point of failure.

If you are sure of that things are even easier. He can connect the gauge to the end of the P supply and read relief pressure there. That completely eliminates the loader and 3pt.

Dan
 

PoTreeBoy

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If thats the case the main system relief becomes a potential point of failure.

If you are sure of that things are even easier. He can connect the gauge to the end of the P supply and read relief pressure there. That completely eliminates the loader and 3pt.

Dan
I'm sure. There is an access panel below the seat. Unfortunately, the drop speed control shaft goes through it, so removing it can be tricky if the knob doesn't want to come off.
1000007571.png
 
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12251hd

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M6800, L35, RTV
Nov 23, 2018
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Thanks, Thats were I am at. I have been hosing the damn thing down with grease cleaner and looking for any new areas. I don't see anymore leaks, last one was at the pioneer coupler, thats fixed now. I am thinking about the two Orings at the front pump, but will get the pressure measurements first, as I may be replacing it anyway.
One final thought. Sitting in the seat, at your left heal is an access to a valve that adjusts the hyd flow to the loader and PB. I accidently moved that valved that impacted my loader and PB. You might check it to see if it got moved.
 

Russell King

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Fout posts up from yours.

First image is my gauge that I am using
Second pic is where the Tee is. I removed the line from the P on the FEL controller and installed the Tee there.
Third pic is the new Pioneer coupler on the PB (some people are concerned for leaks there), and the selector is in BH mode.
Last pic, is confirmation that I have the right line (PB). Since the machine is new to me I verified that the T and PB lines were not reveresed because I removed it from the tractor and have it directly from the PB to the return at the back.

I will put the gauge in the PB line tomorrow and either cap it or use the PB line and uncouple it and get a reading.
I meant on the requested and any future hydraulic pressure tests you do, please post a picture of the gauge position. That way there is less problem understanding your results.
 
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DrHz

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L35
Jun 8, 2026
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Alright not much exciting, kinda what I expected here is the result of placing the gauge at the PB with it capped off. Looks like 700psi with no levers being pushed engine running at 2000 RPM.
 

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DrHz

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L35
Jun 8, 2026
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I'm sure. There is an access panel below the seat. Unfortunately, the drop speed control shaft goes through it, so removing it can be tricky if the knob doesn't want to come off.
View attachment 177645
I just did the PB pressure with it capped off, which is low. Forgive my lack of konwledge on this, but that would cut this relief valve out of the picture wouldn't it?
 
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DrHz

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L35
Jun 8, 2026
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One final thought. Sitting in the seat, at your left heal is an access to a valve that adjusts the hyd flow to the loader and PB. I accidently moved that valved that impacted my loader and PB. You might check it to see if it got moved.
Are you talking about the relief valve that PoTreeBoy was referring to in the post above yours, or a different one? When I am sitting on my tractor the only thing I see at my left heel is the front wheel drive shifter. As I said I am new to this tractor, I have no clue where everything is. Thanks.
 

12251hd

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M6800, L35, RTV
Nov 23, 2018
70
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8
Woodbridge, VA
Are you talking about the relief valve that PoTreeBoy was referring to in the post above yours, or a different one? When I am sitting on my tractor the only thing I see at my left heel is the front wheel drive shifter. As I said I am new to this tractor, I have no clue where everything is. Thanks.
Sorry, I am not near my tractor and cannot give you a good description. But years ago I had to replace the corroded metal delivery lines that go from the front top of the tranny area (under the seat) to the loader. I had to remove the face plate where the 3 pt control rod goes through to disconnect them. There is a valve that you can control with a screw driver blade that controls the hyd flow to the loader/PB. I inadvertedly moved that valve, which affected the flow to the loader. I was thinking there is an open access port to that valve without taking the face plate off, but could be wrong.
 

PoTreeBoy

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I just did the PB pressure with it capped off, which is low. Forgive my lack of konwledge on this, but that would cut this relief valve out of the picture wouldn't it?
No, the relief valve is upstream of the loader valve. I think the best thing now is to remove and look at the relief valve. See post 42, but you just checked the pressure another way, so no need to do that part. BTW, what pressure did you read? Im not sure how the knob comes off that you need to remove that access panel. I'll try to find out.

Edit, there is/are roll/split/spring pins holding the knob on. Use a small punch and some backup to drive it out.
1000007576.png
 
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PoTreeBoy

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In the meantime, here's the guts of the relief valve. The WSM doesn't cover disassembly and cleaning the relief valve, only adjusting and I posted that procedure earlier. But it's not unusual on these older tractors for a piece of old hose or something similar to foul things up. I don't know if a new valve is available.
1000007575.png
Kubota shows the relief valve 'orderable' at my default dealer, but I've had that become NLA before. It's ~$330.
 
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PoTreeBoy

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Are you talking about the relief valve that PoTreeBoy was referring to in the post above yours, or a different one? When I am sitting on my tractor the only thing I see at my left heel is the front wheel drive shifter. As I said I am new to this tractor, I have no clue where everything is. Thanks.
That valve is behind the same cover as the relief valve. You can check that the slot is horizontal, but if it was 180° off, you wouldn't get any pressure at the loader valve.
 

DrHz

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L35
Jun 8, 2026
27
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3
TX
No, the relief valve is upstream of the loader valve. I think the best thing now is to remove and look at the relief valve. See post 42, but you just checked the pressure another way, so no need to do that part. BTW, what pressure did you read? Im not sure how the knob comes off that you need to remove that access panel. I'll try to find out.

Edit, there is/are roll/split/spring pins holding the knob on. Use a small punch and some backup to drive it out.
View attachment 177714
Alright well that gives me some things to look at. I will be traveling until Friday, so I wont be able to get too deep into it until the weekend. Thanks everyone for the direction. Hopefully will get this thing going one piece at a time. in the meantime here is the schematic for the hydraulics for anyone interested. The relief valve is exactly like PoTreeBoy said.
 

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DrHz

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L35
Jun 8, 2026
27
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That valve is behind the same cover as the relief valve. You can check that the slot is horizontal, but if it was 180° off, you wouldn't get any pressure at the loader valve.
Figured I would at least take the panel off and see if I could see that valve and if it was turned. Well looks like nobody has been in this compartment since 2001. Gave'r a good powerwash and now I can see whats what, but I still dont recognize that other valve that @12251hd was talking about. Maybe this model didn't have one? If someone see's it in the pic can you point it out to me? TY. I see the relief, but I'll wait until I get back so everything is good and dry before I take that apart. Any tricks/pointers on disassembly cleaning and reassembly that I should know about?

Okay, took me a while but I found the part on Messicks. They had it under the directional valve assembly diagram. It is available so even if it is bad and I can't get it right I can replace it. So I guess the question now is. Do I crank it closed with the gauge on directly on the P line and see if the pressure goes up to where it is supposed to be? If so then fix/replace? Or just take it out clean it and put it back in hoping that I fixed it and try to adjust it into the right specs? Thanks again.
 

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PoTreeBoy

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Figured I would at least take the panel off and see if I could see that valve and if it was turned. Well looks like nobody has been in this compartment since 2001. Gave'r a good powerwash and now I can see whats what, but I still dont recognize that other valve that @12251hd was talking about. Maybe this model didn't have one? If someone see's it in the pic can you point it out to me? TY. I see the relief, but I'll wait until I get back so everything is good and dry before I take that apart. Any tricks/pointers on disassembly cleaning and reassembly that I should know about?

Okay, took me a while but I found the part on Messicks. They had it under the directional valve assembly diagram. It is available so even if it is bad and I can't get it right I can replace it. So I guess the question now is. Do I crank it closed with the gauge on directly on the P line and see if the pressure goes up to where it is supposed to be? If so then fix/replace? Or just take it out clean it and put it back in hoping that I fixed it and try to adjust it into the right specs? Thanks again.
That directional valve is circled in green.
1000007579.png
Edit, crank what closed? BTW, the P line at the loader is also after the relief. That directional valve is part of a double banjo arrangement, I think, with the relief on the other side. The valve only bypasses the loader, it doesn't bypass the relief valve.
 
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DrHz

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L35
Jun 8, 2026
27
1
3
TX
That directional valve is circled in green.
View attachment 177730
Edit, crank what closed? BTW, the P line at the loader is also after the relief. That directional valve is part of a double banjo arrangement, I think, with the relief on the other side. The valve only bypasses the loader, it doesn't bypass the relief valve.
huh thats a valve?? Ok will check on that one. First things first.....

PSA: If you are going to try and pressure wash your transmission like I did check on the left hand side (dipstick side) for a breather. If your's is installed cover/protect it, if not plug the hole. Guess I will be draining and filling the trans again before I can start it back up.
 

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