Hydraulic Problems

Tx4wheeler71 · May 26, 2022

Hello,

I have a yanmar 3110D that I have owned for many years.

while using the front end loader to move snow I accidentally had the bucket tilted down, and drove forward where it seemed to bind up. After this the bucket tilt no longer functions. It will tilt down, but won’t tilt up without some help. The 3 point will no longer work either. Odd thing is that the up and down on the front end loader seems to work fine and so does the power steering Just no 3 point or tilt on the bucket.

I have made sure it is full of fluid and checked the filter. There is fluid being pumped through the hoses, but I’m not sure how much pressure there should be. The fluid goes through the loader valves before going to the 3pt.

I cleaned the divider but didn’t find any trash. Took the pump off today and it seems fine as well. No play, key is intact and the coupler is fine.

I hate to order a $500 pump if that isn’t the problem. Forgot to mention I took the loader control valves apart and cleaned them as well.

Any ideas that you may have would be appreciated.

ponytug · May 26, 2022

Welcome to TBN!

Hmm. I am no Yanmar expert. My first thought would be to suspect that the impact ruptured a seal in your cylinder, or your loader control valve. My prime bet would be an o-ring on the loader valve. If valve goes into bypass, it will dump hydraulic fluid to the tank, and keep the 3-point from working. The loader portion has priority and will get power to operate. I would either take it to a hydraulic shop, or crack it open to see whether the seals /o-rings are ok. If you don't want to open it to check, I would just buy yourself a hydraulic pressure gauge and a Tee fitting with matching male/female fittings for your hoses to check the cylinder, but that wouldn't explain the lack of the 3-point function, which is caused, I suspect, by a lack of pressure in the power beyond in your loader valve.

All the best,

Peter

winston1 · May 27, 2022

Are you plumbed with power beyond? Might consider swapping loader curl hoses and lift hoses and see what happens. If lift stops working and curl starts working then the loader valve would have to be the culprit.

rScotty · May 27, 2022

Tx4wheeler71 said:
Hello,

I have a yanmar 3110D that I have owned for many years.

while using the front end loader to move snow I accidentally had the bucket tilted down, and drove forward where it seemed to bind up. After this the bucket tilt no longer functions. It will tilt down, but won’t tilt up without some help. The 3 point will no longer work either. Odd thing is that the up and down on the front end loader seems to work fine and so does the power steering Just no 3 point or tilt on the bucket.

I have made sure it is full of fluid and checked the filter. There is fluid being pumped through the hoses, but I’m not sure how much pressure there should be. The fluid goes through the loader valves before going to the 3pt.

I cleaned the divider but didn’t find any trash. Took the pump off today and it seems fine as well. No play, key is intact and the coupler is fine.

I hate to order a $500 pump if that isn’t the problem. Forgot to mention I took the loader control valves apart and cleaned them as well.

Any ideas that you may have would be appreciated.

I doubt it is the pump since your power steering and loader lift arms still work.

The key seems to be that the 3pt doesn't work. My assumption is that means the 3pt is powered by a power beyond hose from the loader valve to the 3pt area. Have you checked flow through that hose? I'm betting you have little to no flow in it.

As to what went wrong, we need to point to something that affects the bucket AND the 3pt .... but not the rest of the system. My best guess is that the relief valve portion of the loader control valve opened suddenly when you hit the obstruction and is somehow stuck open. There is a strong spring in the relief valve assembly that normally keeps the relief valve shut so that flow goes to the power beyond port. That spring may be broken or the relief valve otherwise disabled.
An open relief valve would bypass the 3pt because it would dump all the flow back through the return line instead of into the power beyond pressure line to the 3pt.

On most loader control valves the relief valve assembly is easy to disassemble, check, clean, and adjust.
In fact, mechanicially the relief valve is similar to what you are calling the "divider" - which I'm thinking is technically the "proportional control valve" for the loader vs the power steering - and that's one that you have already that you already checked and cleaned.

That loader relief valve is where I'd look next.
rScotty