Newbie with an L35

[DrHz]

2025 Form 1040-V
Question follows, you can skip the drama straight to it below.

So... I bet many of you have been there. I can fix anything (or so my wife tells me). I bought a broken L35 as opposed to a working one to save some cash. The original story was that the owner had dumped the backhoe to do some 3 point work, pulled up to the house for a drink and bathroom, came out hopped on, and it would no longer move. Of course, the honest seller stated that it only needed a hydraulic pump and would be good to go. These things are indestructible.

When I bought it, the unit was sitting in the dirt and neither the power steering nor the transmission would work. The front bucket would go up and down slowly. So, I figured, yeah, I guess it could be a pump. I got it to my house and, nothing would work anymore. At this point the backhoe is still off. I started snooping around and found that the suction feed tube on the suction filter plate had a huge hole in it and was covered over with a piece of rubber hose. Apparently, (I assume) he had not applied oil to the filter and it was seized on to the plate. He must have tried channel locks or vice grips to hold it still and almost tore the pipe off. I had a hell of a time getting it off myself. I could not find a replacement so I had it repaired and put it back on.

Now I am back to where we were before, except that the power steering mostly works, but it is on a driveway not on dirt, and the front bucket goes up and down faster (not full speed) but still will not pick up the front end. I have changed the O ring at the transmission suction tube, the rubber tubes from the transmission pickup to the filter plate and filter plate to the feed tube, main feed to the power steering/gst pump, so I shouldn’t be picking up air.

Questions:

• I have read on posts to check a sample of hydraulic fluid from the transmission. I bought a syphon with about 24” of tube and fed it in through the filler hole and nothing. No oil. The dipstick says full. Can someone with an L35 please tell me how long the measurement part of your filler gauge is? Maybe mine is a replacement and too long?
• Also if this is not how you are checking your sample please enlighten me or post a link to where this is already delt with?
• I could have two bad pumps, but barring the coincidental demise of two pumps at once doesn’t it sound like air in the system if everything is weak and no transmission movement?
• Has anyone with an L35 checked the pressures at the check ports (D, E, F in the drawing) on the transmission? Can you share with me where they are?

Thanks in advance!

 

[TheOldHokie]

2025 Form 1040-V
Question follows, you can skip the drama straight to it below.

So... I bet many of you have been there. I can fix anything (or so my wife tells me). I bought a broken L35 as opposed to a working one to save some cash. The original story was that the owner had dumped the backhoe to do some 3 point work, pulled up to the house for a drink and bathroom, came out hopped on, and it would no longer move. Of course, the honest seller stated that it only needed a hydraulic pump and would be good to go. These things are indestructible.

When I bought it, the unit was sitting in the dirt and neither the power steering nor the transmission would work. The front bucket would go up and down slowly. So, I figured, yeah, I guess it could be a pump. I got it to my house and, nothing would work anymore. At this point the backhoe is still off. I started snooping around and found that the suction feed tube on the suction filter plate had a huge hole in it and was covered over with a piece of rubber hose. Apparently, (I assume) he had not applied oil to the filter and it was seized on to the plate. He must have tried channel locks or vice grips to hold it still and almost tore the pipe off. I had a hell of a time getting it off myself. I could not find a replacement so I had it repaired and put it back on.

Now I am back to where we were before, except that the power steering mostly works, but it is on a driveway not on dirt, and the front bucket goes up and down faster (not full speed) but still will not pick up the front end. I have changed the O ring at the transmission suction tube, the rubber tubes from the transmission pickup to the filter plate and filter plate to the feed tube, main feed to the power steering/gst pump, so I shouldn’t be picking up air.

Questions:

• I have read on posts to check a sample of hydraulic fluid from the transmission. I bought a syphon with about 24” of tube and fed it in through the filler hole and nothing. No oil. The dipstick says full. Can someone with an L35 please tell me how long the measurement part of your filler gauge is? Maybe mine is a replacement and too long?
• Also if this is not how you are checking your sample please enlighten me or post a link to where this is already delt with?
• I could have two bad pumps, but barring the coincidental demise of two pumps at once doesn’t it sound like air in the system if everything is weak and no transmission movement?
• Has anyone with an L35 checked the pressures at the check ports (D, E, F in the drawing) on the transmission? Can you share with me where they are?

Thanks in advance!

Taking oil samples is tilting at windmills. Test pressure at the pump.

Dan

 

[DrHz]

Taking oil samples is tilting at windmills. Test pressure at the pump.

Dan

Hi Dan, Thanks for the reply. If the pressure is low at the pump, there is no way that it is caused by air from the suction side? I thought if you had air infiltration that the foamed oil will not be able to develop higher pressures hence the decreased power in the system? Is there a range that even with air in the system I should be above for pressure? Thanks

 

[TheOldHokie]

Hi Dan, Thanks for the reply. If the pressure is low at the pump, there is no way that it is caused by air from the suction side? I thought if you had air infiltration that the foamed oil will not be able to develop higher pressures hence the decreased power in the system? Is there a range that even with air in the system I should be above for pressure? Thanks

Low pressure at the pump can be caused by multiple things. But you diagnose the system by starting at ground zero and thats the pump. If pressure is low you diagnose that. If pressure is good you move downstream.

Since your loader is not working as it should you likely have a pump problem. A pump pressure test will tell you one way or the other.

Dan

 

[DrHz]

Great, will do. However, that leads me to another question then. I do not currently have a gauge set that will work for this tractor. Does anyone have suggestions on the most economical set that works for what I will need on this? Should only need it a few times in the rest of my life right???

And while I wait for suggestions and the gauges to come in, I might as well tinker so any other answers to the above questions would be great. Thanks.

 

[TheOldHokie]

Great, will do. However, that leads me to another question then. I do not currently have a gauge set that will work for this tractor. Does anyone have suggestions on the most economical set that works for what I will need on this? Should only need it a few times in the rest of my life right???

And while I wait for suggestions and the gauges to come in, I might as well tinker so any other answers to the above questions would be great. Thanks.

A 3000 PSI gauge will cover most of your needs

https://a.co/d/07bcKw5d

Add a short 1/4" hydraulic hose and a handfull of hydraulic sdapters to hook up to various points on the tractor's jydraulic system.




Then educate yourself on how to take and interpert measurements.

Dan

 

[PoTreeBoy]

2025 Form 1040-V
Question follows, you can skip the drama straight to it below.

So... I bet many of you have been there. I can fix anything (or so my wife tells me). I bought a broken L35 as opposed to a working one to save some cash. The original story was that the owner had dumped the backhoe to do some 3 point work, pulled up to the house for a drink and bathroom, came out hopped on, and it would no longer move. Of course, the honest seller stated that it only needed a hydraulic pump and would be good to go. These things are indestructible.

When I bought it, the unit was sitting in the dirt and neither the power steering nor the transmission would work. The front bucket would go up and down slowly. So, I figured, yeah, I guess it could be a pump. I got it to my house and, nothing would work anymore. At this point the backhoe is still off. I started snooping around and found that the suction feed tube on the suction filter plate had a huge hole in it and was covered over with a piece of rubber hose. Apparently, (I assume) he had not applied oil to the filter and it was seized on to the plate. He must have tried channel locks or vice grips to hold it still and almost tore the pipe off. I had a hell of a time getting it off myself. I could not find a replacement so I had it repaired and put it back on.

Now I am back to where we were before, except that the power steering mostly works, but it is on a driveway not on dirt, and the front bucket goes up and down faster (not full speed) but still will not pick up the front end. I have changed the O ring at the transmission suction tube, the rubber tubes from the transmission pickup to the filter plate and filter plate to the feed tube, main feed to the power steering/gst pump, so I shouldn’t be picking up air.

Questions:

• I have read on posts to check a sample of hydraulic fluid from the transmission. I bought a syphon with about 24” of tube and fed it in through the filler hole and nothing. No oil. The dipstick says full. Can someone with an L35 please tell me how long the measurement part of your filler gauge is? Maybe mine is a replacement and too long?
• Also if this is not how you are checking your sample please enlighten me or post a link to where this is already delt with?
• I could have two bad pumps, but barring the coincidental demise of umps at once doesn’t it sound like air in the system if everything is weak and no transmission movement?
• Has anyone with an L35 checked the pressures at the check ports (D, E, F in the drawing) on the transmission? Can you share with me where they are?

Thanks in advance!

Here's a picture of my trans dipstick. The marks, not visible, are at 3/8" and 3/4" from the tip. Edit: oops, forgot the picture.

The part in your second photo is the filter base, part of the suction piping. I can assure you that crimp is affecting your hydraulic flow. Mine had the pipe from the sump to the part in your photo partially crushed when I got it. I was able to open it by driving a round nose rod/bolt/rivet down the tube while supporting it in a vise, then bending it back to shape.

 

[12251hd]

I go back to your original post that you had a hole in the suction hose. I hope you have replaced suction and pressure side hose at the filter. Next, I would check the pump that you don't have debris (from the suction hole). The only time I've had (hyd pressure) issues on my L35 is leaking hose at filter. Good luck.

 

[Russell King]

Do as @TheOldHokie suggested and start with proper diagnosis on the pump.

Since you are in Texas, there is a good chance that there is a good hydraulic shop somewhere near you (The Wilson Company), that will have the gauge, hose and fittings sitting on the shelf. They are inexpensive and easily obtained.

You will also need some adapters to fit into the test ports so you need to get those also. The manual may tell you the sizes of the ports for those test points. I would also think the manual would show pictures of the test ports on the tractor so read through the manual to see if it describes where to test. The ports are probably BSPP thread (also known as DIN G designation). Your Kubota dealer should be able to tell you the location and size of the ports.

If you are near Austin I have a gauge you can borrow but honestly they are around $15 so you could spend that much on gas getting it.

 

[DrHz]

Here's a picture of my trans dipstick. The marks, not visible, are at 3/8" and 3/4" from the tip. Edit: oops, forgot the picture.
View attachment 177201
The part in your second photo is the filter base, part of the suction piping. I can assure you that crimp is affecting your hydraulic flow. Mine had the pipe from the sump to the part in your photo partially crushed when I got it. I was able to open it by driving a round nose rod/bolt/rivet down the tube while supporting it in a vise, then bending it back to shape.

Thanks for the pic. Mine looks like the right one I guess. I didn't see your second picture in the post. Since you cannot order the filter plate I ended up cutting off the pipe that was all torn up and mig welding a replacement pipe on it. No leaks so I assume it is good to go.

 

[DrHz]

Do as @TheOldHokie suggested and start with proper diagnosis on the pump.

Since you are in Texas, there is a good chance that there is a good hydraulic shop somewhere near you (The Wilson Company), that will have the gauge, hose and fittings sitting on the shelf. They are inexpensive and easily obtained.

You will also need some adapters to fit into the test ports so you need to get those also. The manual may tell you the sizes of the ports for those test points. I would also think the manual would show pictures of the test ports on the tractor so read through the manual to see if it describes where to test. The ports are probably BSPP thread (also known as DIN G designation). Your Kubota dealer should be able to tell you the location and size of the ports.

If you are near Austin I have a gauge you can borrow but honestly they are around $15 so you could spend that much on gas getting it.

Thanks for the info. I am up in Celina (McKinney area). Looks like there is a Wilson about 50 min from me. I am going to have to make a stop there at the end of the week.

 

[Russell King]

Thanks for the info. I am up in Celina (McKinney area). Looks like there is a Wilson about 50 min from me. I am going to have to make a stop there at the end of the week.

There are probably a bunch of hydraulic shops closer than 50 miles. The Wilson Company is good but so are most of them.

Good luck, just be sure you get an adapter from the gauge thread to the hose fitting along with some from the hose to the tractor. Getting JIS female swivel ends on the hose makes life pretty easy to buy an adapter from JIS to whatever thread the port or gauge has.

 

[Russell King]

@DrHz

There is a member vendor that sells what you need on line. (I forgot they had hydraulic stuff)

Hydraulic Tools - BoltOnHooks LLC

Bolt-On Hooks and Hydraulic Tools for compact tractors.

www.boltonhooks.com

 

[DrHz]

@DrHz

There is a member vendor that sells what you need on line. (I forgot they had hydraulic stuff)

Hydraulic Tools - BoltOnHooks LLC

Bolt-On Hooks and Hydraulic Tools for compact tractors.

www.boltonhooks.com

Thanks

 

[DrHz]

I go back to your original post that you had a hole in the suction hose. I hope you have replaced suction and pressure side hose at the filter. Next, I would check the pump that you don't have debris (from the suction hole). The only time I've had (hyd pressure) issues on my L35 is leaking hose at filter. Good luck.

Are you suggesting a complete teardown of the pump(s)?

 

[TheOldHokie]

Are you suggesting a complete teardown of the pump(s)?

Test it first.

Dan

 

[PoTreeBoy]

While you're waiting for a gauge, you can do a quick and easy flow test of the front (implement) pump. Below is a picture of my valve when I had it off. The leftmost ports are P and T, the upper one should be P, coming from the pump discharge. Disconnect this line and place it in a clean container. Start your tractor at a low to medium RPM. You should see a fairly strong flow of fluid, 11 gpm at full throttle. You can't run it long or you'll empty the sump. You can reuse the fluid, assuming it is clean.

The rightmost port, easily seen while sitting on the tractor, is the power beyond port. You can also do the same flow test there, if it's easier. The flow will be from the valve, not the hose, of coutse.

 

[TheOldHokie]

While you're waiting for a gauge, you can do a quick and easy flow test of the front (implement) pump. Below is a picture of my valve when I had it off. The leftmost ports are P and T, the upper one should be P, coming from the pump discharge. Disconnect this line and place it in a clean container. Start your tractor at a low to medium RPM. You should see a fairly strong flow of fluid, 11 gpm at full throttle. You can't run it long or you'll empty the sump. You can reuse the fluid, assuming it is clean.

The rightmost port, easily seen while sitting on the tractor, is the power beyond port. You can also do the same flow test there, if it's easier. The flow will be from the valve, not the hose, of coutse.
View attachment 177309

Empirical and so easy!

Dan

 

[12251hd]

Are you suggesting a complete teardown of the pump(s)?

I always start with the simple things first. Check the suction hose. I've replaced mine a couple times over 20 years--easy to get punctured or worn down from brush. A small leak is a tell-tale sign. Debris could have gotted sucked in your puncture and collect at the connection going to the pump. That is a HD, high GPM pump and I would not automatically assume it would go bad all at once is my point. But it could be failing. Good luck.

 

[TheOldHokie]

The filter head was mangled and you had if "repaired".

The hose in the suction pipe was punctured and you replaced it.

Your dipstick is missing and you don''t even know how much oil is in the sump.

You have a lot of questionable things going there. Do as @PoTreeBoy advised and see if you are getting oil and if so how nuch from the pump. If you are getting oil you can measure the flow rate and pressure. Its simple abd definitive. Armed with that information you can make an informed deternination of where to look next.

Dan