Hello all. Looking for some wisdom. I was mowing much of the day yesterday with my L4150 and everything fine. Then in the early evening I noticed the oil pressure light come on. I also have installed a gauge that also read zero. What could have happened? (The engine still ran).
L4150 Lost Oil Pressure
- Thread starter nlefmann
- Start date
You could have several different problems. From as simple as 2 failed sensors or as complex as a failed oil pressure pump. First check the oil level and all of the oil lines for a leak. If the oil level is full, I would not run the engine until you make sure you have pressure to pump oil to the engine bearings.
Steve.
Steve.
Thanks Steve. I'm afraid it's not a sensor since the secondary oil pressure gauge I installed is not electric and has worked fine until this occurred. Engine oil is full although looks dirty. I will change oil & filter but still afraid to run it any more until I figure out what happened. Looking for help!
Russell King
Well-known member
Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
I would assume that the oil pump is not working. It could be the pump or what drives the pump is broken. It might be simply that the oil pickup broke off somehow.
See here for illustrated parts list
apps.kubotausa.com
The pickup is in the oil pan section and the pump is in the crank case section. The pump appears to be driven by gears and is under a front cover of the engine.
From what I see I would drain the oil and drop the oil pan first to verify if the pickup is still intact and the screen on it is clean or clogged. Beyond that I would probably replace the o ring on the pickup tube if it seems it is loose at all.
If nothing there the move to the front cover removal and see what is going on behind there with the pump. That is much more work to get to (I assume).
See here for illustrated parts list
Kubota Tractor Corporation - Illustrated Parts List
- K-PAD - Parts Lists - Illustrated Parts Lists - diagrams
The pickup is in the oil pan section and the pump is in the crank case section. The pump appears to be driven by gears and is under a front cover of the engine.
From what I see I would drain the oil and drop the oil pan first to verify if the pickup is still intact and the screen on it is clean or clogged. Beyond that I would probably replace the o ring on the pickup tube if it seems it is loose at all.
If nothing there the move to the front cover removal and see what is going on behind there with the pump. That is much more work to get to (I assume).
I would assume that the oil pump is not working. It could be the pump or what drives the pump is broken. It might be simply that the oil pickup broke off somehow.
See here for illustrated parts list
Kubota Tractor Corporation - Illustrated Parts List
- K-PAD - Parts Lists - Illustrated Parts Lists - diagrams
The pickup is in the oil pan section and the pump is in the crank case section. The pump appears to be driven by gears and is under a front cover of the engine.
From what I see I would drain the oil and drop the oil pan first to verify if the pickup is still intact and the screen on it is clean or clogged. Beyond that I would probably replace the o ring on the pickup tube if it seems it is loose at all.
If nothing there the move to the front cover removal and see what is going on behind there with the pump. That is much more work to get to (I assume).
Thank you Russell. I was afraid that's what I would hear from the Orange sages! No time right now so it may be a while before I post what I find.
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
If the oil pump has failed it will be the first one I've ever seen fail.
I've seen 20K hours on these engines and the oil pumps are like new still.
It's more likely that the relief valve.
Super easy to get to and check.
I've seen 20K hours on these engines and the oil pumps are like new still.
It's more likely that the relief valve.
Super easy to get to and check.
Thanks Wolfman - I was just looking at that part and wondering if it could possibly be related to my issue. Can it be cleaned or should I buy a new one?
Today I installed a new relief valve and o ring, changed the oil and put on a Kubota filter. Had high hopes but still no oil pressure. Should I drop the pan next?
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Yes I would drop the oil pan next and check for pickup issues, then if you still don't get anything you'll have to open it up even further.
Have you opened up the oil port pressure port and cranked or run it to check for any oil flow?
Wolfman - I have to admit I don't know what/where the oil port pressure port is. Are you talking perhaps about removing the Comp Relief Valve at the filter or should I be looking somewhere else?
on the side of the engine there are a few plugs. Some of them are "drive-in" plugs, as some call them "freeze" plugs or "welch" plugs. They close off intersecting oil passages, and some of them are on the suction side of the oil pump. If one of those falls out, it will have zero oil pressure. I've seen this numerous times on some of the L series (L35 comes to mind....). Best I remember, RH side of the engine near or on the gearcase.
Thanks so much. I'll definitely give both sides of the block a good close look and let you know what I find. BTW I've never encountered a freeze plug that did not seal off a water passage. Never knew that they were also used for oil passages.
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Pull the oil pressure sensor off and see if you get any oil flow.
Russell King
Well-known member
Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
@North Idaho Wolfman is referring to the point where your oil pressure gauge line attaches to the engine.
If you remove the small tube at the engine attachment point and crank the engine there should be oil that exits that hole. I would avoid starting the tractor, just crank it but not start it. If it does start then turn it off quickly or you may have a mess.
Depending upon where the point is you might be able to cover it with a rag to prevent the mess.