Slow Moving Loader

[Frbe62]

The BF400 loader on my L235DT was moving slow. I checked and cleaned the hydraulic quick-connects and it worked great for a short time. So I decided to replace the quick-connects. The loader worked great until I loaded it with a full bucket of dirt. I had a hard time lifting the bucket, it raised extremely slow. I dumped the load and the loader seemed to work good. I let the tractor sit for a couple of hours and checked the loader which raised up great. I dropped the bucket and attempted to raise it again but it raised extremely slow. Any idea on what the problem could be? One of the bucket tilt cylinders is leaking (not too badly) but the fluid level is up to par. The loader control valve appears to be an original factory control valve from the early 1980's (1983?). The three point hitch has worked perfectly throughout the troubles with the loader. I have no problem quickly raising a 5' box blade.
Any help you tractor wizards can offer would be greatly appreciated.

Thanks,
Fred

 

[Dave_eng]

The BF400 loader on my L235DT was moving slow. I checked and cleaned the hydraulic quick-connects and it worked great for a short time. So I decided to replace the quick-connects. The loader worked great until I loaded it with a full bucket of dirt. I had a hard time lifting the bucket, it raised extremely slow. I dumped the load and the loader seemed to work good. I let the tractor sit for a couple of hours and checked the loader which raised up great. I dropped the bucket and attempted to raise it again but it raised extremely slow. Any idea on what the problem could be? One of the bucket tilt cylinders is leaking (not too badly) but the fluid level is up to par. The loader control valve appears to be an original factory control valve from the early 1980's (1983?). The three point hitch has worked perfectly throughout the troubles with the loader. I have no problem quickly raising a 5' box blade.
Any help you tractor wizards can offer would be greatly appreciated.

Thanks,
Fred

Fred

Plse provide more detail about your tractor and FEL. Is the FEL installed from the factory by Kubota.

Without much doubt you have a hose connected to the wrong port on the FEL valve or one of your new quick couplers is not seated fully.

You would be surprised how many owners get into this problem making changes or fixing leaks.

How many hoses connect to your FEL valve block.?

Can you post a picture of the FEL valve and hoses.

Another possibility, although remote, (pun intended) is that a control valve somewhere on your tractor, possibly a rear remote, is not in the middle or neutral position. When this happens the high pressure needed for the hydraulics is being bled off by the partially or fully stuck open valve.

Don't go tearing stuff apart. This is going to be a simple problem once we get all the details from you and you re check things carefully.

Dave

 

[Frbe62]

Dave,

Thanks for the reply. The FEL appears to be an original install by Kubota. There are 7 hoses connected to the FEL valve block, six on the back side and one on the end. Several photos of the valve are attached. The tractor came with what appears to be power assist steering that is not working. There are no hoses connected to the cylinder connected to the steering. I'm not familiar with the hydraulic control valve that leads to the steering and I guess, the FEL.

Thanks so much for your help,
Fred

 

[Dave_eng]

Fred

The parts info on Messicks.com shows for your BF400 FEL valve a valve block built up in sections bolted together.

Does your valve look like a series of sections bolted together?

I have added number 1 to 6 ports on the valve assembly in red.

Can you try and trace each of those 6 lines and tell me where each goes.

For example 1 & 2 likely go to either the boom cylinders or the bucket cylinders
3 & 4 also go to boom or bucket cylinders.

Presently on the parts illustration, I only see 6 ports but I don't doubt there is a 7th as you have stated. It would be the power beyond port likely going to the steering control valve.

If the power steering was working before you started your coupler replacement project, this is a good indication some hose is in the wrong place.

If you don't have the owner's manual go to Kubotabooks.com and download it.

There are shown optional hydraulic outlet possibilities in the hydraulics section of the manual. Flange type outlet or Threaded Boss type outlet.

If you compare your tractor to the illustration in the owners manual you will be able to tell me which system you have.

Try and repeat your photos with more light or a flash as they are too dark for me to make out critical detail.

Are there any letters or numbers beside any of the ports on the FEL valve assembly? Perhaps a P or T

Dave

 

[stumpcutter]

is it just lift on loader? does buckett curl and dump ok? does loader lift ok without load try switching lift and lower lines

 

[Dave_eng]

is it just lift on loader? does buckett curl and dump ok? does loader lift ok without load try switching lift and lower lines

Owner previously provided this additional clue that has arisen concurrent to the FEL issues:

The tractor came with what appears to be power assist steering that is not working

Likely the High pressure carry over or power beyond line is not going to the steering control valve as it should but somewhere else

Dave

 

[Frbe62]

Hello Stumpcutter,

The loader worked fine for the 2 years I've had it but it started slowing down. Now the lift is very slow and curling the bucket up is also slow. No problem with lowering or curling the bucket down. The loader is now lifting and curling slow without a load.

Thanks for your help,
Fred

 

[Frbe62]

Dave,

I'll take some better photos of the control valve. It's going to be two weeks before I can get back to the tractor. I'll also look for letters next to each of the ports.

The power steering was not working when I bought the tractor two years ago. There were no hoses connected to the steering cylinder when I bought it.

I changed each quick connect one at a time so I don't see how they could be crossed. After changing the quick connects the loader worked perfectly until I tried to lift a full load of dirt. Then the loader lifted extremely slow with the load. I dumped the load and the loader raised up fine. I put the tractor in the barn and tried the loader again and it raised extremely slow with no load. The bucked worked slow curling the bucket up also.

I have both the Kubota Owners and Workshop manuals. I will look over the section on the power beyond port and take some photos of what's controlling the loader and power steering.

Thanks,
Fred

 

[stumpcutter]

need to check hydraulic pressure at loader control valve. does loader valve have pressure relief valve? might have trash blocking flow remove and clean it BUT DO NOT ADJUST WITH OUT PRESSURE GAUGE HOOKED UP.

 

[MagKarl]

What do you have for screens or filters? Have you cleaned or replaced them?

 

[North Idaho Wolfman]

Cylinder seal failure have been totally left out of this conversation!

Swap hoses just on the up and down lines to the cylinders.
If it has the same exact issue, slow / weak lift, you have bad / blown cylinder seals, it could be only one of the 2 cylinders but you should rebuild both at the same time.

Same goes for the curl!

 

[Frbe62]

Wolfman,

I will try your suggestion. IThe lift cylinders were both rebuilt less than 50 hours ago. I changed the hydraulic fluid and filter at the same time. The rebuilder would not guarantee one of the rebuilds because of a scratch on the rod. That cylinder has leaked since it was rebuilt and installed and the leak has gotten worse.

I have found aftermarket replacement cylinders that should match up pretty close to the originals. The rod and bore size may be slightly larger. Replacement cylinders will cost me about 1/2 of what it will cost to have the rod replaced on one cylinder and the other rebuilt. Is there a good reason to stick with the original orange cylinders?

Thanks for your help Wolfman!

 

[Frbe62]

Hello MaGKarl,

There is a canister hydraulic filter on this machine. The hydraulic fluid and filter were changed less then 50 hours ago when both tilt cylinders were rebuilt.

Thanks,
Fred

 

[Frbe62]

Wolfman,

I told you that the lift cylinders were rebuilt, that was wrong. The bucket tilt cylinders were rebuilt not the lift cylinders.

Fred

 

[Frbe62]

Wolfman,

One tilt cylinder has leaked since I bought the tractor. That cylinder continued to leak after it was rebuilt. I ordered two new tilt cylinders. I***8217;ll change the cylinders and let you know what happens.

Thanks,
Fred

 

[North Idaho Wolfman]

One tilt cylinder has leaked since I bought the tractor.

The leak you are having is internal not external, so you won't see it.

 

[Frbe62]

Wolfman,

I swapped the lines and the loader and 3 pt lift are still slow (no change) The tractor is about an hour away from my home. I received two new tilt cylinders Friday and intended to replace them but I left the fittings at the house. It will be a couple of weeks before I can get back out there to change the tilt cylinders.

Fred

 

[Frbe62]

Dave,

I pulled the control valve off and found a tag on it. After cleaning it up good with a wire brush it appears to be an original Kubota valve. You should also clearly be able to see the 7 lines connected to the valve. The photos of the control valve are attached.

I swapped out the hydraulic lines as he North Idaho Wolfman suggested. There was no change to the speed in loader movement.

Fred

 

[Frbe62]

Cylinder seal failure have been totally left out of this conversation!

Swap hoses just on the up and down lines to the cylinders.
If it has the same exact issue, slow / weak lift, you have bad / blown cylinder seals, it could be only one of the 2 cylinders but you should rebuild both at the same time.

Same goes for the curl!

Hello Wolfman,

I swapped the hoses out and the loader and 3 pt hitch still lift slow. I replaced both tilt cylinders and still no change. I exchanged the lift cylinders with one of the tilt cylinders and still no change. I did notice that when the tractor was shut down and sat for a minute the loader would start off lifting slow but got really slow after a minute or so. I pulled the hydraulic filter to see if there could be anything clogging it and it looked like it was capturing a lot of debris. The fluid that came out of the filter was somewhat discolored with a brownish/blackish tint and it looked like there were several black solid specks falling out of the filter the size of a pin head. I bought an new Hydraulic filter and will change the fluid the next time I'm back out there where the tractor is.

I also remember adjusting the 3pt lift lever just before having problems with the loader lift. There are 3 or four washers behind the inside nut on the threaded shaft coming out of the cast housing. Could this have anything to do with the loader lift problem?

Thanks,
Fred

 

[Dave_eng]

Dave,

I pulled the control valve off and found a tag on it. After cleaning it up good with a wire brush it appears to be an original Kubota valve. You should also clearly be able to see the 7 lines connected to the valve. The photos of the control valve are attached.

I swapped out the hydraulic lines as he North Idaho Wolfman suggested. There was no change to the speed in loader movement.

Fred

7 lines at the FEL valve block indicate a power beyond installation.

Do you have power steering?

If not then the hydraulic pressure flow is first to the FEL valve and then the 3 pt and rear remotes if any.

I see the letters KYB on the FEL valve which is a large international company.
I provide this link only to show you about KYB
https://www.kyb.co.jp/media/hydraulics_products_guide_en.pdf

Try and look for letters on the FEL block around each port.

As you have said the 3 pt lifts a large snow blower without a problem, and you have power beyond in the FEL valve, I am still suspicious of a hose in the wrong place.

Could you try and make a simple sketch of the FEL valve, trace each hose and then indicate it on the sketch.

Dave