B3030 Hydraulic power

[alaept]

Hi,

I have a Kubota B3030 with 168 hours on it. The hydraulics just don't seem to be as strong lately as I remember them to be. I noticed it last time I was digging with the BH (or was it just hard ground?).

Yesterday, I was digging a post hole on a slope and raised the front end with the FEL. It could barely lift the front end, I had to repeatedly engage the hydraulics, getting maybe a 1/4" at a time (at 2000RPM). I just seem to remember that it could pick itself up easier than that. My old Case 580 could do it at idle.

What do you think? Should a B3030 be able to lift itself up with the FEL? If so, any idea what I can do to diagnose the problem?

Thanks!

Dick

 

[J_J]

You should be able to lift the front end off the ground easily.

Did you perhaps go into regen on the valve.

Check your relief pressure on the FEL valve.

Set it to 50 psi below the pumps max pressure.

Make sure there is no back pressure caused by the 3pt.

Install a 3000 hyd gage in the IN port of the FEL valve and you can see the pressure caused by the cyl load.

 

[alaept]

You should be able to lift the front end off the ground easily.

Did you perhaps go into regen on the valve.

Check your relief pressure on the FEL valve.

Set it to 50 psi below the pumps max pressure.

Make sure there is no back pressure caused by the 3pt.

Install a 3000 hyd gage in the IN port of the FEL valve and you can see the pressure caused by the cyl load.

Sorry in advance for the novice questions, but what do you mean by "regen on the valve"? I simply pointed my bucket down and pushed the FEL control forward.

OK, thanks, I've looked at some of the posts that mention how to check the hydraulic pressure and will find a gauge somewhere ready-made, or will build one:
http://www.tractorbynet.com/forums/...172-bxpanded-hydraulic-pressure-test-kit.html

If the pressure is OK, then perhaps the flow is impeded?? I've seen mention of a screen that can get partially blocked by debris in the hydraulic oil. (Dunno where it lives though ...)

The 3-pt was simply holding up an implement (dangling in air). What conditions would cause a 3pt hitch implement to cause back pressure?

Thanks!

Dick

 

[Monster5601]

I've seen mention of a screen that can get partially blocked by debris in the hydraulic oil. (Dunno where it lives though ...)
Dick

As far as I know, the B3030 doesn't have a screen, just two filters for the hydraulic pump. I know some tractors do have a screen, but not this one.

My B3030 easily lifts the front of the tractor, even when idling. This is a long shot since everything is hydraulically driven but did you do the 50 hour service which includes replacing the two hydraulic filters?

 

[J_J]

Sorry in advance for the novice questions, but what do you mean by "regen on the valve"? I simply pointed my bucket down and pushed the FEL control forward.

OK, thanks, I've looked at some of the posts that mention how to check the hydraulic pressure and will find a gauge somewhere ready-made, or will build one:
http://www.tractorbynet.com/forums/...172-bxpanded-hydraulic-pressure-test-kit.html

If the pressure is OK, then perhaps the flow is impeded?? I've seen mention of a screen that can get partially blocked by debris in the hydraulic oil. (Dunno where it lives though ...)

The 3-pt was simply holding up an implement (dangling in air). What conditions would cause a 3pt hitch implement to cause back pressure?

Thanks!

Dick

If you place your bucket flat on the ground, and curl down, you may have two modes. Power mode and regen/fast dump

As you push the lever to the curl down, you may have a soft stop. Past that point is the regen mode, where the bucket will provide a fast dump /low power for curl.

If you only give the curl down about half lever, it should lift the front end.

Some tractors only have a simple 3pt system, and if you leave the lever in the up position, you pressurize the hyd path, and that is back pressure working against your pump flow.

 

[Monster5601]

If you place your bucket flat on the ground, and curl down, you may have two modes. Power mode and regen/fast dump

As you push the lever to the curl down, you may have a soft stop. Past that point is the regen mode, where the bucket will provide a fast dump /low power for curl.

If you only give the curl down about half lever, it should lift the front end.

Some tractors only have a simple 3pt system, and if you leave the lever in the up position, you pressurize the hyd path, and that is back pressure working against your pump flow.

The B3030 doesn't have either of the features you discussed but the loader controls are feathered.

 

[Ductape]

The regen circuit on the Kubota is opposite the JDs........ where the JDs have (from left to right on the stick) the curl, neutral, dump, then regen. Kubotas have curl, neutral, regen, then dump. Gotta push past the detent on the kubota to get to the power dump circuit.

 

[J_J]

If Monster5601 is correct, then he needs to do a pressure check on the FEL relief valve.

He should be able to lift the front end using curl and lift functions.

 

[alaept]

As far as I know, the B3030 doesn't have a screen, just two filters for the hydraulic pump. I know some tractors do have a screen, but not this one.

My B3030 easily lifts the front of the tractor, even when idling. This is a long shot since everything is hydraulically driven but did you do the 50 hour service which includes replacing the two hydraulic filters?

Thanks for the info. I bought my tractor at 113 hours. The previous owner said that the 100 hour maintenance items were accomplished. I think I'll check the pressure, and if an adjustment is called for, I'll change the oil and filters along with making the adjustment. That should just about cover it.

One more question. If I adjust the hydraulic pressure as measured at the FEL relief valve, does that set the hydraulic pressure for the whole machine (BH, HST, etc.)? Or are there other circuits to check and adjust?

Thanks,

 

[J_J]

The FEL valve adjustment is just for the implement system. Loader, 3pt, remotes, etc

If you have a hydro, they have their own relief settings.

 

[CHDinCT]

I simply pointed my bucket down and pushed the FEL control forward.

To raise your front end, you really need to use the curl function as others mentioned, meaning to push the lever to the right. Pushing down lowers the boom circuit and once your bucket is on the ground it won't go too much further so it won't lift the front end much. If the curl down function doesn't lift it easier and higher, then it would confirm some issue with your hydraulic system.

 

[alaept]

To raise your front end, you really need to use the curl function as others mentioned, meaning to push the lever to the right. Pushing down lowers the boom circuit and once your bucket is on the ground it won't go too much further so it won't lift the front end much. If the curl down function doesn't lift it easier and higher, then it would confirm some issue with your hydraulic system.

Thanks Chris, I assume (perhaps wrongly) that if I curl the bucket to the dump position and push down on the boom that it should lift the front. There's plenty of rod showing on the hydraulic cylinders, so I know it's not out of travel. Also, I do it this way because it doesn't mess up the ground as much as using the curl to lift the machine.

So I guess this begs the question... The boom has a lot of power lifting, but does it have as much power pushing down? Is the force applied by the cylinder symmetrical regardless of direction?

I have a BXpanded pressure tester on order ...

 

[Ductape]

No, the hydraukic cylinders always have more force when extending. When retracting, you lose the area that the rod takes up.

 

[J_J]

Thanks Chris, I assume (perhaps wrongly) that if I curl the bucket to the dump position and push down on the boom that it should lift the front. There's plenty of rod showing on the hydraulic cylinders, so I know it's not out of travel. Also, I do it this way because it doesn't mess up the ground as much as using the curl to lift the machine.

So I guess this begs the question... The boom has a lot of power lifting, but does it have as much power pushing down? Is the force applied by the cylinder symmetrical regardless of direction?

I have a BXpanded pressure tester on order ...

2 in cyl
1 in rod
3000 psi

Extend force = 9 425 lbs
Retract force = 7,069 lbs

If you lift the bucket and then curl down, you then should be able to lift the front end using the lift cyl any time.

As far as which cyl are more powerful between the lift cyl and the curl cyl, it would depend on the size of the cyl, using one or two cyl in the curl circuit, and mechanical relationship of the cyl mounting points.

B3030

Loader specs

Breakout force (at pin): 2,313 lbs [1049 kg]
Breakout force (at 500mm): 1,690 lbs [766 kg]
Lift to full height (at pin): 1,091 lbs [494 kg]
Lift to full height (at 500mm): 783 lbs [355 kg]