L1500 oil light

[bob2492]

I recently received a Kubota L1500 from a friend. It has a bushhog front loader.
My friend had used the tractor for years mowing with a 4’ hog and had little trouble. Last year he replaced the Hydralic pump. He had bought a newer Kubota and this one sat in the pasture for a year or so. When I got it, I changed the oil, filter and coolant. With a new battery it fired right up. In 15 seconds or so, the oil light came on and stayed. My friend said it had just started that and if you dropped the bucket and lifted the tractor slightly he light would go off and it does just that. I checked the wire to the light (from the sending unit) and it is tight with good continuity.

I put a new oil sending unit in today and fired the tractor right up.
Waited 10 or 15 seconds and the oil light came on. Lifted the tractor with the bucket and it
Went out. Let it warm up and dropped the bucket, light came on again. Drove the tractor up on blocks to raise the front of the tractor without the bucket and the light stayed on. Lifted the tractor with the bucket again and it went out. In that position it will idle fine and the light stays off.

Tried getting the light to go out by lifting the bucket as high as it would go and light stayed on. Tried using the rear lift and turned on PTO and light stayed on. Dropped the bucket again, light goes off.

I plan to fit a mechanical gauge to see what the pressure is really doing, but have a feeling the light is okay.

Seems to be tied to the bucket being pushed down enough to lift the tractor. I know the Engine oils and Hydraulic system are only connected mechanically. Any ideas?

Thanks

 

[ipz2222]

recheck th oil level and if it shows full, add 1 qt. Pickup screen may have come off pump.

 

[bob2492]

Thanks,
will the extra oil hurt?

 

[DickSnyder]

My L185DT had a similar oil light mystery. As a last resort, I cut off about 1/2" of the wire to the sender, put on a new ternimal and light worked as should. Just a thought, might see if that helps. Good luck.
Dick.

 

[bob2492]

Thanks, if that works, can I use it with extra oil or do I need to pull pump?

 

[bob2492]

Installed a mechanical oil pressure gauge and cranked the tractor. 5 to 10 lbs oil pressure at Idle. Pushed down with bucket and pressure went to 50 lbs+. I shut it off and checked oil and it was full to the upper limits on the dip stick. I added a quart of oil and restarted it. Idle pressure went to 30 lbs and raised up to 50 lbs at 2500 rpm with the bucket off the ground. Pushed down on bucket and idle pressure went to 50 lbs and up to 60 lbs at 2500. Drove it done the road and back and pressure ran about 40 lbs. Again at idle back to 30 lbs bucket up, push bucket down, 50 lbs. Removed the oil pressure bypass spring and ball. Looked clean, but I cleaned them anyway and it seemed to make no difference in pressure.

Checked the Hydraulic fluid level and it was overfilled. Drained to proper level but no difference in tractor lift or oil pressure fluctuations. (I have this theory that when the Hyd pump was changed, somehow the oil flow to the drive gear (engine oil) is constricted? Can that happen?)

Anyway, there is a small crack at the front of the block that has been welded, it seeped very little before, but with an extra quart of oil it now has, is seeping more noticeably.
I will bleed that extra quart back out soon. I found a bare block for $350 here in state, but that is something I want to avoid. Any luck having blocks welded?
Tractor cranks and operates very well otherwise.

Any ideas? Thanks

 

[ipz2222]

When you first pushed down with bucket, did you raise the eng speed first?

 

[ipz2222]

If that crack is not in a pressure area, it can be cleaned," really good" and jb weld put on top of it. Heat the area slightly before adding the jb weld, makes it set better.