Loader Getting Weak With Use?

[Soopitup]

I've noticed that my loader has less lifting power at the end of the day.

When the tractor is cold (not ran) and I start it running at idle I have no problem lifting the front loader ( 2023 BX23S).
It's very slow, but it has no problem lifting and curling the bucket.
Once I've ran it for a while at idle it doesn't want to lift the bucket at all.

Same RPMs (14 - 1500)

It's hard to tell how much power loss I have at 3500 RPMs and a full bucket. Loads are always different.

I get hydraulic fluid gets worn out, but this was happening even at just past 30 hours (I'm at 48 now).
It's not that hot here (hottest it's been is mid 70s, and only for a few hours. Usually in the 50s or 60s.
Operating mostly in shade.
HST fan is fine.
I'm using the bucket to it's capacity; lifting very heavy wet topsoil. Driving moderate speed (I don't want to tear up my lawn too bad) just under 150 feet, dump and return. So there's some bouncing.
This isn't full pace worksite speed, it's homeowner speed (stops for kids, ect).

Is this normal? I would think it would take more than this to weaken it, but I'm still getting used to this tiny thing.
I've used the backhoe, haven't noticed anything, but haven't done any specific tests either.

 

[85Hokie]

The fluid is not worn out rather the heat has caused the flow to increase. Thick oil will hold that pressure a bit better than hot less viscous oil.

I would get out of idle in either case, babying the machine does no good at all - YOU want the fluid to flow well, the pump needs to run at a level that will allow fluid to push the cylinders smoothly. YOU do not have to raise the bucket any faster than normal but having the pump run a bit better in it's range will help.

I too have noticed that lift capacity it directly related to hot oil vs cool oil, and I have my pressure shimmed up from the start, so I understand what you are describing.

 

[TheOldHokie]

I've noticed that my loader has less lifting power at the end of the day.

When the tractor is cold (not ran) and I start it running at idle I have no problem lifting the front loader ( 2023 BX23S).
It's very slow, but it has no problem lifting and curling the bucket.
Once I've ran it for a while at idle it doesn't want to lift the bucket at all.

Same RPMs (14 - 1500)

It's hard to tell how much power loss I have at 3500 RPMs and a full bucket. Loads are always different.

I get hydraulic fluid gets worn out, but this was happening even at just past 30 hours (I'm at 48 now).
It's not that hot here (hottest it's been is mid 70s, and only for a few hours. Usually in the 50s or 60s.
Operating mostly in shade.
HST fan is fine.
I'm using the bucket to it's capacity; lifting very heavy wet topsoil. Driving moderate speed (I don't want to tear up my lawn too bad) just under 150 feet, dump and return. So there's some bouncing.
This isn't full pace worksite speed, it's homeowner speed (stops for kids, ect).

Is this normal? I would think it would take more than this to weaken it, but I'm still getting used to this tiny thing.
I've used the backhoe, haven't noticed anything, but haven't done any specific tests either.

The loader is losing power because something in the circuit is bypassing and you are loosing pressure.
When the oil warms up it thins out and the oil bypasses easier and you lose more pressure.

You need to identify the source of the bypass. Most likely sources are the pump itself or the piston seals in the loader cylinder. I would start by pressure testing the pump.

Start with the tractor cold. Disconnect the hose supplying oil to the loader valve and connect a 5000 PSI pressure gauge to the end of the hose. Start the engine and read the pump discharge pressure when cold. Reconnect the hose and run the tractor for a while until its hot and you start to lose loader lift. Shut the tractor off, connect your pressure gauge as you did previously, start the tractor and read pump discharge pressure again. It should be the same as it was when cold. If not the pump is worn or the main pressure relief valve is leaking.

Dan

Glycerine Filled Pressure Gauges, 2.5 in Diameter, 0-5000 PSI

304 stainless steel case, Plexiglass crystal, Pointer is balanced aluminum, black finish, dial is aluminum, white background, Bottom connection 1/4’’ NPT brass.

www.baileyhydraulics.com

 

[GreensvilleJay]

What I've learned in the past 5 years, 1200 hrs...
1500 RPM is idle
2500 is light working loader or backhoe, travel on level ground
3000 is heavy duty use(full buckets, quicker digging)

if you want to compare use, then you have to haul the same loads, same distances. Having different loads ..you can't make honest evaluation.

At 50 hrs , you do full, complete oil changes, both engine and HST ( check the manual.....)
if the dealer's doing this,have them check the PSI of the hydraulics.

Also be sure to add a screen filter on the tank and... spray rustcheck or other 'thickish oil' on the back hoe controls under the plastic cover.

 

[Nate77]

Run the tractor with the backhoe off, or still on for counter weight but hydraulics unhooked. I went trough something similar when my 2021 was brand new. Dealer had to replace the backhoe valve block, luckily it was under warranty, the repair would have cost $2500.

 

[NorthwoodsLife]

I was taught in the 1970's by my uncle, a farmer and big rig owner operator for his life: To NEVER lug a diesel and NEVER run attachments at idle. Wether that be the loader, the 3 point, etc. Even turning the steering wheel if is hydraulic. Too low RPM's will cause blowby on your rings. A diesel is a big flywheel machine and loves to run, and not be bogged down. If you slow the flywheel without RPM's it puts greater load on the pistons, crank, etc etc.

Also, diesels die young with constant turn on and shut offs.
I'm amazed seeing online videos of people turning on and off thier tractors everytime they dismount. Unless I'm done working for an a 1/2 hour, I let her run.
I also drop all the implements before shut off.

Now, that's how I was taught and had a B7100 go up to 2,500 hours with no problems. Sold it after that so I don't know when, if ever, it failed the new owner.
Don't be afraid of reving it, within the breakin guidelines in your manual. You must seat those rings.
Maybe today's diesels are different, and maybe there are those on here that can correct me.

And...
Heated hydraulics loose power. Always have. Heating anything expands it. So your hydro pump has to push fluid through bigger lines.

 

[imnukensc]

There's nothing wrong with your tractor or its hydraulics.

 

[NorthwoodsLife]

@TheOldHokie Said:
"The loader is losing power because something in the circuit is bypassing and you are loosing pressure.
When the oil warms up it thins out and the oil bypasses easier and you lose more pressure".

Respectfully Sir or Ma'am, You are correct, but incorrect.
As the machine heats up the hydraulic lines expand, and the oil becomes thinner. Therefore the hydraulic pump has to work harder because the oil is thinner and the lines, rubber or otherwise, have expanded. Losing lift capacity and pressure is normal. Because the line expand and the fluid thins. All the while the pumps capacity remains constant.

At this juncture, pulling lines and attaching pressure gauges is extreme, on a brand-new tractor.

As @imnukensc said, At this point there is nothing wrong with the OP's tractor.

 

[Soopitup]

The loader is losing power because something in the circuit is bypassing and you are loosing pressure.
When the oil warms up it thins out and the oil bypasses easier and you lose more pressure.

You need to identify the source of the bypass. Most likely sources are the pump itself or the piston seals in the loader cylinder. I would start by pressure testing the pump.

Start with the tractor cold. Disconnect the hose supplying oil to the loader valve and connect a 5000 PSI pressure gauge to the end of the hose. Start the engine and read the pump discharge pressure when cold. Reconnect the hose and run the tractor for a while until its hot and you start to lose loader lift. Shut the tractor off, connect your pressure gauge as you did previously, start the tractor and read pump discharge pressure again. It should be the same as it was when cold. If not the pump is worn or the main pressure relief valve is leaking.

Dan

Glycerine Filled Pressure Gauges, 2.5 in Diameter, 0-5000 PSI

304 stainless steel case, Plexiglass crystal, Pointer is balanced aluminum, black finish, dial is aluminum, white background, Bottom connection 1/4’’ NPT brass.

www.baileyhydraulics.com

That's what I'm wondering. I didn't think it should be doing this, but I wasn't sure.

This thing isn't even 2 months old, with just under 50 hours.
I've been tempted to throw some pressure gauges on the dash to monitor.

Funny how the 5000 PSI are so much cheaper than the 3000 PSI gauges....

What I've learned in the past 5 years, 1200 hrs...
1500 RPM is idle
2500 is light working loader or backhoe, travel on level ground
3000 is heavy duty use(full buckets, quicker digging)

if you want to compare use, then you have to haul the same loads, same distances. Having different loads ..you can't make honest evaluation.

At 50 hrs , you do full, complete oil changes, both engine and HST ( check the manual.....)
if the dealer's doing this,have them check the PSI of the hydraulics.

Also be sure to add a screen filter on the tank and... spray rustcheck or other 'thickish oil' on the back hoe controls under the plastic cover.

Yes, I'm not using the bucket at idle, just raising it up after I start the engine.
I didn't really notice anything while working, just noticed when I was letting it idle and cool it couldn't raise the bucket.
I'll be doing it, I've intended to check the pressure anyways, I guess I'll have to do some digging.
I hate warranty work. Especially when I'm not the one getting paid.

I was taught in the 1970's by my uncle, a farmer and big rig owner operator for his life: To NEVER lug a diesel and NEVER run attachments at idle. Wether that be the loader, the 3 point, etc. Even turning the steering wheel if is hydraulic. Too low RPM's will cause blowby on your rings. A diesel is a big flywheel machine and loves to run, and not be bogged down. If you slow the flywheel without RPM's it puts greater load on the pistons, crank, etc etc.

Also, diesels die young with constant turn on and shut offs.
I'm amazed seeing online videos of people turning on and off thier tractors everytime they dismount. Unless I'm done working for an a 1/2 hour, I let her run.
I also drop all the implements before shut off.

Now, that's how I was taught and had a B7100 go up to 2,500 hours with no problems. Sold it after that so I don't know when, if ever, it failed the new owner.
Don't be afraid of reving it, within the breakin guidelines in your manual. You must seat those rings.
Maybe today's diesels are different, and maybe there are those on here that can correct me.

And...
Heated hydraulics loose power. Always have. Heating anything expands it. So your hydro pump has to push fluid through bigger lines.

When I raise it it's only first thing while it's cold, to idle it out of the garage. Doesn't lug or bog at all. Engine note doesn't change even the slightest bit. Even when it's hot and won't raise the engine runs perfect. It just doesn't seem to have enough pressure (haven't put a gauge on it yet).
The steering does bog it a little at idle. I don't normally run it that way. It's a straight shot out of the garage so doesn't need much steering.
And yeah, I let it run too. I rarely shut it off in the middle of work either.
I spent 8 years working on diesels in the Marines.

I wouldn't think the small change from the heat should cause this, especially since it's not even 2 months old and less than 50 hours, but I don't know what's "normal" with these yet.

I'll have to check the pressures and see. I definitely want to figure this out now.

Actually, now that I think about it, I got a free 50 hour service when I bought this thing.
I wasn't going to use it because I don't have a trailer for it yet so I'd have to pay for transport.
If it's going to go in for warranty work anyways, might as well get the free service.
Now if I can just find a trailer to borrow.

 

[TheOldHokie]

@TheOldHokie Said:
"The loader is losing power because something in the circuit is bypassing and you are loosing pressure.
When the oil warms up it thins out and the oil bypasses easier and you lose more pressure".

Respectfully Sir or Ma'am, You are correct, but incorrect.
As the machine heats up the hydraulic lines expand, and the oil becomes thinner. Therefore the hydraulic pump has to work harder because the oil is thinner and the lines, rubber or otherwise, have expanded. Losing lift capacity and pressure is normal. Because the line expand and the fluid thins. All the while the pumps capacity remains constant.

At this juncture, pulling lines and attaching pressure gauges is extreme, on a brand-new tractor.

As @imnukensc said, At this point there is nothing wrong with the OP's tractor.

With all due respect that is nonense.

IF (big if) he is losing power when the tractor warms up something is wrong.

Pump discharge pressure should never drop below relief setting hot or cold. If it does the pump is defective and bypassing internally.

He may well be inexperienced and tilting at windmills but there is nothing extreme about a simple inexpensive pump discharge pressure test. New products can be defective and he might even learn something In the process.

Or he can do as leveraddict said below - take it to the dealer and let them check it out.

Dan

 

[leveraddict]

Take it back to the dealer!

 

[Fastball714]

I have a B3300 that does this. I found out that the 3 point lift has to be in the neutral position. You pull it forward to lower and return lever to the neutral position after adjusting height. If it's not centered, the lift is very very slow. The bucket will tilt fine.
I'm not sure if your tractor has the same type levers to control the 3 point lift. I sprayed a little oil to help lever return to neutral. It was letting hyd fluid bypass the fel lift. This was the first tractor that I've seen that the 3 point lift control had a neutral position.

 

[TheOldHokie]

I have a B3300 that does this. I found out that the 3 point lift has to be in the neutral position. You pull it forward to lower and return lever to the neutral position after adjusting height. If it's not centered, the lift is very very slow. The bucket will tilt fine.
I'm not sure if your tractor has the same type levers to control the 3 point lift. I sprayed a little oil to help lever return to neutral. It was letting hyd fluid bypass the fel lift. This was the first tractor that I've seen that the 3 point lift control had a neutral position.

All 3pt valves have a neutral position. How that position is managed varies. On tractors with position control its automatic and transparent to the operator. On tractors without position control (e.g. BX) the operator has to center the valve.

Current generation Kubota loader valves have a serial spool on the boom crcuit.. If ANY downstream valve is not in neutral it can and probably will block operation of the boom cylinders on the loader.

You can easily demonstrate that using just the loader. Raise the boom to mid height, roll the bucket to full back and hold the joystick there. Now try to raise or lower the loader with the joystick held in the bucket roll position. The loader will be hydraulically locked and the pump will unload through the relief. Move the bucket spool back to neutral and lift works fine.

Dan

 

[Soopitup]

As the machine heats up the hydraulic lines expand, and the oil becomes thinner. Therefore the hydraulic pump has to work harder because the oil is thinner and the lines, rubber or otherwise, have expanded. Losing lift capacity and pressure is normal. Because the line expand and the fluid thins. All the while the pumps capacity remains constant.

At this juncture, pulling lines and attaching pressure gauges is extreme, on a brand-new tractor.

As @imnukensc said, At this point there is nothing wrong with the OP's tractor.

The pump shouldn't be at absolute 100% capacity. Even if the fluid is hot and the loader is at it's max lift.
It's very very very rare to have something engineered to run at it's absolute max. There's almost always somewhat of a buffer built in.
There are relief valves and bypasses built in for that reason.

I can't imagine the pump/valves wouldn't be able to keep up with slight swelling of the hoses and thinning of the fluid.
Especially since
The tractor is basically brand new still.
It wasn't that hot of a day.
I wasn't running it at full tilt.

However, this doesn't necessarily mean there's something wrong with the tractor.
The only difference I could confirm right now is at idle. At that point the pump is well below full flow and power, so the thinner fluid could have an impact.

What I need to do is check at full RPM and preferably with a load.
Maybe I'll drag some bags of pellets back out and do a timed lift cold and hot.

I've moved almost all of that very heavy wet dirt, so I'll need to find something heavy I can stress it with.
I already have a pressure gauge, however I need to get some fittings I think, so I can do this as simple as possible (I don't think all the connections are the same, even the quick connects?).

I need to figure it out soon, because there's no sense in me spending money on the service parts if it's got to go in anyways (I got a free 50 hour service).

 

[Soopitup]

Take it back to the dealer!

Not keen on that.
I don't trust them to do a good job, especially if there's not an obvious problem.

I have a B3300 that does this. I found out that the 3 point lift has to be in the neutral position. You pull it forward to lower and return lever to the neutral position after adjusting height. If it's not centered, the lift is very very slow. The bucket will tilt fine.
I'm not sure if your tractor has the same type levers to control the 3 point lift. I sprayed a little oil to help lever return to neutral. It was letting hyd fluid bypass the fel lift. This was the first tractor that I've seen that the 3 point lift control had a neutral position.

I have a backhoe attached. I haven't touched the 3 point controls at all.
I'll double check next time I'm out there but I doubt that's it.
Thank you for the suggestion though.

All 3pt valves have a neutral position. How that position is managed varies. On tractors with position control its automatic and transparent to the operator. On tractors without position control (e.g. BX) the operator has to center the valve.

Current generation Kubota loader valves have a serial spool on the boom crcuit.. If ANY downstream valve is not in neutral it can and probably will block operation of the boom cylinders on the loader.

You can easily demonstrate that using just the loader. Raise the boom to mid height, roll the bucket to full back and hold the joystick there. Now try to raise or lower the loader with the joystick held in the bucket roll position. The loader will be hydraulically locked and the pump will unload through the relief. Move the bucket spool back to neutral and lift works fine.

Dan

I haven't specifically done the exact test you outlined, but I've definitely had the loader control very close to full roll (in or out) and had no problem raising/lowering the loader. Slower, but it works just fine.
I'll have to remember to do exactly as you outlined, I'm curious.

 

[TheOldHokie]

The pump shouldn't be at absolute 100% capacity. Even if the fluid is hot and the loader is at it's max lift.
It's very very very rare to have something engineered to run at it's absolute max. There's almost always somewhat of a buffer built in.
There are relief valves and bypasses built in for that reason.

I can't imagine the pump/valves wouldn't be able to keep up with slight swelling of the hoses and thinning of the fluid.
Especially since
The tractor is basically brand new still.
It wasn't that hot of a day.
I wasn't running it at full tilt.

However, this doesn't necessarily mean there's something wrong with the tractor.
The only difference I could confirm right now is at idle. At that point the pump is well below full flow and power, so the thinner fluid could have an impact.

What I need to do is check at full RPM and preferably with a load.
Maybe I'll drag some bags of pellets back out and do a timed lift cold and hot.

I've moved almost all of that very heavy wet dirt, so I'll need to find something heavy I can stress it with.
I already have a pressure gauge, however I need to get some fittings I think, so I can do this as simple as possible (I don't think all the connections are the same, even the quick connects?).

I need to figure it out soon, because there's no sense in me spending money on the service parts if it's got to go in anyways (I got a free 50 hour service).

I believe the pump discharge hose is a female JIC swivel. All you should need fir a discharge pressure test is a male JIC adapter for the gauge. Probably -08 but possibly -06.

The size of the hoses means nothing - you could replace them all with hoses 10 times as laege and pressire and flow does not change. The loader will lift just vas much and at the same speed.

It does not sound like you really have a good handle on this "problem".. Maybe a test will ease your concerns.

Dan

 

[imnukensc]

I'll say it again for anyone that missed it the first time. There is nothing wrong with the OP's tractor or its hydraulics.

 

[GreensvilleJay]

re: The only difference I could confirm right now is at idle. At that point the pump is well below full flow and power, so the thinner fluid could have an impact.

Every pump has a minimum speed (RPM) that it will work. All pumps are rated for xx GPM @ yyy RPM. The BX23s is no different in that respect.I've found 2500 to be good for moving mountains of compost, full buckets,moderates ground speed. For pallet forking, 2000 is better as it slows down the loader movement

 

[85Hokie]

re: The only difference I could confirm right now is at idle. At that point the pump is well below full flow and power, so the thinner fluid could have an impact.

Every pump has a minimum speed (RPM) that it will work. All pumps are rated for xx GPM @ yyy RPM. The BX23s is no different in that respect.I've found 2500 to be good for moving mountains of compost, full buckets,moderates ground speed. For pallet forking, 2000 is better as it slows down the loader movement

I'll second and third what he said ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 

[lugbolt]

there's nothing wrong with it. Normal for that tractor. That tractor's hydraulic pump is TINY in regards to flow. The pump has a pair of gears inside of it which mesh together and are "sealed" at the ends between the gears and housing. When the fluid warms up to operating temp (which, btw is roughly 100 deg above ambient temp), the pump parts expand and the amount of leakage between the gears and also between the gears & the housing increases. Because the pump is so tiny, any leakage is felt by a loss of hydraulic power.

Secondly, since the pump is so teeny tiny, and the flow rate is so little, at idle they're very, very weak. You have to increase the engine speed in order to make the pump develop any pressure and flow. That is the big downside to these glorified lawn mowers. They're not really "tractors" per say, although they have all the features that a larger tractor does, just scaled way down.

Brand new ones that I dealt with on dealer lots were all like this. All the BX's were/are the same way.

Running at idle speed also tends to reduce coolant flow through the radiator and reduces airflow across the radiator, both can lead to overheating. Increase the engine speed. It's not gonna hurt anything but your ears, use ear plugs if it bothers you.