L2202 hydraulics not working

[shawathome]

Hi,

Bucket and 3pt hitch will not lift. I replaced the pump and it worked fine for a few minutes, then became noisy and jerky and failed to lift correctly. The replacement pump did not resolve the issue.

I double checked and tighten clamps to ensure no air leaks / pump cavitation. Replaced o-rings from banjo fitting at sump through to pump outlet. Control valve is one year old.

Here is the mystery, and where I think a solution can be found. When I completely drain the gearbox/hydraulic oil and also remove and drain the outlet hose, and then refill, it works for a few minutes. The bucket and 3pt lift normally while the tractor is parked. Then I go off to work and within a few minutes the bucket and 3pt will not work, and it becomes noisy and jerky again. This is repeatable.

If I do not drain and bleed the hydraulics (reservoir and outlet to spool valve only) whenever I start and try the hydraulics it will not work and is noisy, shaky / jerky.

Why would it work normal for those few minutes and then all of a sudden not work ?

What in a hydraulic system would allow it to work after a drain, and then not work ?

I'm hoping someone can help me out with this, so I can get back to working with this old tractor. Otherwise, it's been a really good workhorse.

 

[Dave_eng]

A bit more of your tractor's history would help.

What led you to replace the pump?

Were any loader hoses changed or any hoses going to or from the loader valve.

Where did you order the pump? Kubota or other..........

Dave

 

[shawathome]

Thanks, ...

Yes, the OEM pump must have been replaced some time ago. When I got the tractor two years ago it had a KAYABA pump. This pump did have signs of cavitation on the outlet port. The hydraulics also exhibited the same behaviour I'm describing. So I replaced it with :

- 34150-36100 New Kubota L175 L185 L1501 L1801 L225 L2000 L2201 Hydraulic Pump, which shipped from whitehorse tractors in Winnipeg. @ 3.8 gallons per minute.

I installed a new inlet hose and new clamps with this pump and it worked great. A year later I am back with it not working again, so I got another one of the same pumps and installed it thinking that would solve the problem. This time it did not solve the problem, so it seems that it's something else now ?

So, one year with the original pump, then one year with the replacement. Then this problem.

Changing the replacement pump, with yet another replacement pump did not solve the problem.

When I did the first pump replacement I also changed the loader valve. No hoses or anything else. Again, it all worked very well for one year. Not to say the spooler vale has not failed or needs some adjustment.

One thing to note is that both times when the "problem" began I was digging with the loader into rocky (sandstone mix) ground. I now think that I should just stick to piles of dirt and compost. It's probably too much work load for the small tractor. It's a buhler allied 195 arm.

One of the things I also did was to run the engine/pump with the pump outlet hose (inlet hose) to the spool valve disconnected just to see if there was flow. Yes, good flow, but I don't have pressure gauges to test pressure, and am not sure the placement of pressure gauges to troubleshoot.

The noise and the vibration from the hydraulic system when trying to lift the bucket is considerable. However I don't think it's from the pump. I touched the pump when it was trying to lift the bucket and it seemed smooth and noise free. The sound appears to be coming from somewhere else ? Perhaps the spooler valve ... When I put my hand on the hose supplying high pressure oil into the spooler valve it seems to vibrate and has a high frequency squeal. It made me think air leaking into the low pressure side and I have checked and double checked the clamps and seals.

Holding this line has become my test to tell if it's going to work or not. No sound, no vibe, it works. Otherwise I don't even bother to try and lift the bucket because I know that symptom means it will not work.

If there was a low pressure side vacuum air leak into the inlet why would it work well for a few minutes ? I'm talking 2 or 3 full bucket lift and lower cycles, and a few bucket curl cycles. It gets me thinking great, ... I'm good to go, and then it goes back to not working.

I've never adjusted the spooler valve or done anything other than connect the lines.

There is no hydraulic oil filter in the sump on this model, and the external oil filter is clean and good.

I have drained the hydraulic oil from the banjo fitting on the side of the sump and it flows out very well, indicating that there's no plugging/clogging of the oil from the sump into the inlet pipe/hose.

I've taken it all apart 3 or 4 times now checking and double checking the basic things like clamp sealing, fastener torque, etc. The only thing I haven't done is to try spraying hydraulic oil onto connections while it's operating to see for seepage inside to the hoses ?

Could it be something within the 3pt hitch ?

Anyway, I hope this history will help in figuring out a next step to solving this problem. I can always send some photos of anything that would be helpful.


Thanks, Mike

 

[Dave_eng]

Thanks, ...

Yes, the OEM pump must have been replaced some time ago. When I got the tractor two years ago it had a KAYABA pump. This pump did have signs of cavitation on the outlet port. The hydraulics also exhibited the same behaviour I'm describing. So I replaced it with :

- 34150-36100 New Kubota L175 L185 L1501 L1801 L225 L2000 L2201 Hydraulic Pump, which shipped from whitehorse tractors in Winnipeg. @ 3.8 gallons per minute.

I installed a new inlet hose and new clamps with this pump and it worked great. A year later I am back with it not working again, so I got another one of the same pumps and installed it thinking that would solve the problem. This time it did not solve the problem, so it seems that it's something else now ?

So, one year with the original pump, then one year with the replacement. Then this problem.

Changing the replacement pump, with yet another replacement pump did not solve the problem.

When I did the first pump replacement I also changed the loader valve. No hoses or anything else. Again, it all worked very well for one year. Not to say the spooler vale has not failed or needs some adjustment.

One thing to note is that both times when the "problem" began I was digging with the loader into rocky (sandstone mix) ground. I now think that I should just stick to piles of dirt and compost. It's probably too much work load for the small tractor. It's a buhler allied 195 arm.

One of the things I also did was to run the engine/pump with the pump outlet hose (inlet hose) to the spool valve disconnected just to see if there was flow. Yes, good flow, but I don't have pressure gauges to test pressure, and am not sure the placement of pressure gauges to troubleshoot.

The noise and the vibration from the hydraulic system when trying to lift the bucket is considerable. However I don't think it's from the pump. I touched the pump when it was trying to lift the bucket and it seemed smooth and noise free. The sound appears to be coming from somewhere else ? Perhaps the spooler valve ... When I put my hand on the hose supplying high pressure oil into the spooler valve it seems to vibrate and has a high frequency squeal. It made me think air leaking into the low pressure side and I have checked and double checked the clamps and seals.

Holding this line has become my test to tell if it's going to work or not. No sound, no vibe, it works. Otherwise I don't even bother to try and lift the bucket because I know that symptom means it will not work.

If there was a low pressure side vacuum air leak into the inlet why would it work well for a few minutes ? I'm talking 2 or 3 full bucket lift and lower cycles, and a few bucket curl cycles. It gets me thinking great, ... I'm good to go, and then it goes back to not working.

I've never adjusted the spooler valve or done anything other than connect the lines.

There is no hydraulic oil filter in the sump on this model, and the external oil filter is clean and good.

I have drained the hydraulic oil from the banjo fitting on the side of the sump and it flows out very well, indicating that there's no plugging/clogging of the oil from the sump into the inlet pipe/hose.

I've taken it all apart 3 or 4 times now checking and double checking the basic things like clamp sealing, fastener torque, etc. The only thing I haven't done is to try spraying hydraulic oil onto connections while it's operating to see for seepage inside to the hoses ?

Could it be something within the 3pt hitch ?

Anyway, I hope this history will help in figuring out a next step to solving this problem. I can always send some photos of anything that would be helpful.


Thanks, Mike

Mike

Thanks for taking the time to provide a history.

The loader's relief valve should be protecting both the loader and hydraulic system during hard work.

A few questions.

How many hoses on your loader valve, 6 or 7?

A hose from the hydraulic block to the loader valve being connected in the wrong placed at either endcan cause lots of problems.

It will be worthwhile to work through these connections with you.

Some photos of the block and the loader valve please.

Dave

 

[North Idaho Wolfman]

Could be a issue with the tractors relief valve, I would look into that.

 

[shawathome]

Hi Dave,

There are 6 hoses : 1 inlet, 1 outlet, 2 bucket lift, 2 bucket curl

The hoses have been connected the same way since I replaced it last year. All during that time it worked well.


Thanks, Mike

 

[Dave_eng]

It is difficult to find technical material for the L2202DT as it appears to be a Grey Market tractor with no USA equivalent model.

I am assuming your tractor has a hydraulic block and that is where the loader hoses connect.

Could you please take a photo of this area.

The easiest way and place to test the pressure is in one of the valve ports feeding a loader function.

A 0-3,000 psi gauge can be bought for around $30.

If hydraulic oil is constantly being bleed off through a relief valve as NIW suggested to you, it could aerate the fluid and it is only with draining that the air gets released. This is a guess.

Dave

 

[shawathome]

I put the pressure gauge on the inlet side of the spool valve block. Lifting the 3pt gave a reading of around 1000 psi and the lift was normal/ok and hydraulic pump/system sounded good. When lifting the FEL it gave a reading of around 300-400 psi and the lift was slow, and the hydraulic pump/system sounded strained and whinny.

Why does the pump provide 1000 psi to lift the 3pt, but only 400 to try and lift the FEL ?

doesn't the pressure relief valve on the spool set the max pressure to the entire system ?


I also put the pressure gauge on the bucket lift line, same readings. With the pressure gauge on the curl lift line, ... same readings (only around 300 - 400 psi). The Buhler Allied 195 bucket is supposed to be getting 2000 psi.

What would cause the 3pt to work, but the FEL not to work ?



Thanks, Mike

 

[Dave_eng]

Can you make a simple sketch showing where the main hydraulic lines go.

Not the 4 to the FEL arms and bucket but the other lines feeding the loader valve and the 3 pt.

I would have expected to see 7 lines on the loader valve one of which being a power beyond line.

Do you have the installation instructions for the allied loader?

Dave

 

[shawathome]

Hi Dave,

Here is a really basic schematic. The outlet from the spool has a line that goes directly into the o/p cylinder (3pt) under the seat.

Here's the link to the Buhler-Allied loader.

BUHLER ALLIED 195 ASSEMBLY, OPERATOR'S AND PARTS MANUAL Pdf Download

View and Download Buhler Allied 195 assembly, operator's and parts manual online. Allied Loader Operator's and Parts Manual. Allied 195 compact loader pdf manual download. Also for: Allied 95.

www.manualslib.com

I tried adjusting the PRV on the spool. I turned it in, with 1/2 turns each test, and it did not make any difference. The pressure gauge kept reading only 300-400 psi when I raised the bucket. And around 1000 psi when I raised the 3pt. I only turned it in three complete turns, I don't want to break anything.


Mike