B7200HST Weak hydraulics

[Bobbyu]

I have a B7200hst with around 650 hrs on the clock. It has the kubota loader on it. I forget the model. I've owned it about 3yrs. The hydraulics are weak. I've installed a pressure gauge in a line just before the loaders control. I originally got only about 1350psi so I took apart the relief valve. Found no shims there. Not sure if there should be. I installed a couple and raised the pressure about 150psi. Tried a couple more with hardly and noticeable gain. So I'm barking up the wrong tree I believe. The PO must of replaced the pump once before cause it is a diff. color. Where should I check next? I changed all fluids and filters when I got it. Cleaned the suction screen. Really everything look good. Screen didn't have anything in it. Maybe pump is shot. Where is a good place to order new Pump? Don't have a Kubota dealer to close.
Thanks

 

[D2Cat]

You can order parts online. Might try Coleman Equipment in Smithville, Mo. (816-532-8288). They have 3 stores in the greater K.C. area.

 

[Bobbyu]

Thanks D2Cat. Is there something else I should be checking before going after a new pump? Hate to put a new pump on and still have problems.

Thanks
Bob

 

[Dave_eng]

With a loader it is possible you have two relief valves.

The Kubotabooks WSM does not talk about loader hydraulics but does say there is a relief valve built into the control for the 3 pt hitch. Most loader valves have their own relief valve.

I would be cautious about just replacing the pump until you fully understand and have tested your system in the best way to evaluate the pump.

Post some photos of the FEL valve and the pump.

Dave

 

[Bobbyu]

I will get some pictures. Yes the loader does have a relief valve. I have my gauge inline before the loader valve and at best I get about 1450. But for kicks I did turn the loader relief valve in a little just 1/4 turn. No help. I believe the loader is 1630.

 

[Bobbyu]

This what my loader valve looks like.

 

[Dave_eng]

Am I correct that the loader valve has 6 hoses?

Where is the loader valve fed from?

Just for your safety in the future, you should never use plumbing fittings (Tee) in hydraulic circuits. They are not designed for hydraulic pressures and can crack and spray you with a fine stream of fluid which can be injected through your skin. Hydraulic fittings are not too expensive

You do not need a Tee to test relief valve settings. Just connect to one of the loader ports straight on.

How did you do the test you did? Just install the gauge and start tractor? Move loader valve(s)?

You have an Open Center Hydraulic system which means the oil will take the easiest path back to the reservoir unless a valve is directing flow elsewhere. In some circumstances, the lower set relief valve will set the maximum pressure attainable.

Dave

 

[Bobbyu]

I have had the gauge inline for a while. Got pressure reading when using loader to dig dirt and gravel. Good point about the fitting I didn't think I would have them in line for long but they have been now.

Bob

 

[North Idaho Wolfman]

Sounds like you're either not adjusting the relief valves properly or look for suction (large line) side leaks, they will just be wet spots, they will cause you to entrain air and loose hydraulic pressure.

When you move the loader without weight does it move quickly or very slow?

Dave, that valve has 7 lines on it 2 on the back one on the side and 4 on the top, standard configuration.

 

[Bobbyu]

The loader moves slow. The valve does have 7 hoses. 4 of them that come out of the top & go to the loader cylinders, 1 pressure that I have a gauge in, 1 return that comes out of the front of the valve that goes back to the top of the rear end and 1 that comes out of the right side of the valve and goes down to the block where the pressure line comes from. Not sure how I'm adjusting the relief valves wrong but it is entirely possible. The one under the seat with the slotted head nut had no shims. Maybe that is normal. I've put a couple in there between the nut and spring and got very little improvement. The relief valve on the loader valve I've turn in about a 1/4 turn with no difference. My 3pt works. I have to raise the RPM to get it raise my Woods Rm59 mower especially when the oil is hot.
Thanks for the help.
Bob

 

[twomany]

What do you know about the relief valve that is in the block where the pressure comes from? The selector block.

 

[Dave_eng]

What pressure do you see if you leave the gauge where it is on the FEL IN line and raise the 3 pt hitch.

Dave

 

[Dave_eng]

What do you know about the relief valve that is in the block where the pressure comes from? The selector block.

All I valve can find is this block which does not have a relief valve.

Yours could be different.

Dave

 

[twomany]

Yah, Mine has a branch off the back with some sort of relief valve .

That's why I asked, not assuming I know what you have

 

[Dave_eng]

Yah, Mine has a branch off the back with some sort of relief valve .

That's why I asked, not assuming I know what you have

Please post a picture of it.

Dave

 

[Bobbyu]

What pressure do you see if you leave the gauge where it is on the FEL IN line and raise the 3 pt hitch.

Dave

It is about the same as when I use the loader.

 

[Bobbyu]

What do you know about the relief valve that is in the block where the pressure comes from? The selector block.

I might go get a picture of that block. I don't think there is any relief valve there. A vavle to shut or divert the pressure. I'v never done anything with it. I don't think the loader has ever been off since day one but I could be wrong.

 

[Bobbyu]

Please post a picture of it.

Dave

Attached are a couple pics of the valve. Like I said I have never messed with it. Maybe I should. The one picture shows a valve(I think) with nut located between the two hoses the other kind of shows a valve on the top towards the back. It just has a shaft sticking up with a rod. I thought I read somewhere that is to divert the pressure. I'm sure you guys know. thanks again for the help.

Bob

 

[North Idaho Wolfman]

The pressure relief valve on that model is tricky to adjust and I'll bet you tried adjusting the wrong valve.
Some mess with the valve in red and that is not the pressure relief valve, disregard the blue (drop speed adjustment), you want to adjust the yellow if you even need to.

Now a slow loader is normally not a pressure issue it's a flow issue, when was the last time you removed and cleaned or better yet replaced the filter?

 

[Bobbyu]

I've seen your picture before when searching. I adjusted the one behind the slotted head. When I bought the tractor a little over two years ago I dropped all fluids and changed filters and cleaned the suction screen. Oil looked good and the suction screen looked clean. Thought maybe I wasted my time and money but it was good to know for sure. I haven't changed it since. I've only put on a little over a 100hrs on it. I used Kubota UDT2. I think that is what it is called. I thought about getting some more and a new suction screen and replacing both.

Thanks for your ideas.
Bob