Idiot light

[MLD]

My first post. My first kubota.
I may have bought a pig in a poke buying this B7100 . I needed a small tractor but bigger than my Gravelys. The price was right $2500 and 750 hrs. it was very clean for its age no leaks etc. and I knew If I didn't buy it in the morning it would it would be gone in the afternoon. well it purrs like God intended good little tractors to, but after awhile, say 15 minutes of low idle the low oil pressure light came on. So I increased the rpm a little and the light went off.
So I blithely went about my business playing with my new toy when the pesky thing came on again I increased the rpm it came on again. Well I don't know much about tractors but I know about idiot lights so brought it back to the barn. And started calling any one that could help and joined this forum.
Some people say its the sending part thats gone, other say it's the oil pump.
Hopefully with only 750 hrs it's not the pump. I didn't have the oil and filter changed because I was told that it had just been done 20 hrs ago.
There is plenty of oil, black as tar, also normal in diesels I'm told. I have a friend coming with an oil pressure gauge and will change the oil and filter.

Any other tips or suggestions are welcome.

MLD

 

[mjncad]

Try the sending unit first. It's cheap and easy. If it still says low oil pressure, than you can start investigating the expensive stuff.

 

[Blagadan]

I wouldnt worry about it MLD. I had the exact same symptoms with my B7100. The oil pressure light would come on at low idle. Increasing the rpm would turn the oil pressure light out.
Turned out to be a dodgy sender. New unit solved the problem.
Just as well to have your buddy come over and check the pressure just to be sure it isnt something more serious.

You are going to be pleased with your purchase. My B7100 continues to impress me with the amount of work it does.

If you want, I have a handy .pdf user manual for the B7100. PM me with your email and I'll send it on. I'm sure I have some exploded diagrams with part numbers around too, I'll see if I can dig that out.

B

 

[MicroPilot]

You did check the oil level right?

As you said you were gonna do, I'd change the oil anyway. That way YOU KNOW when the last oil change was and don't have to take a sellers biased answer to the question.

 

[RWolf]

Ditto, change the oil. Although it's normal for oil in diesels to get black understanding why it's that way will go a long way to keep your tractor running for a long time. Basically what your seeing is blow by from the cylinders. In gas it doesn't change the color of the oil that much and it takes longer. But in diesels it will happen pretty fast. One of the products of using diesel is the sulphur in it. As it is blown by the cylinder rings it will mix with the oil. As the oil cools down etc. condensation builds up in the crankcase. When you mix sulpher and water in this environment you end up with...sulphuric acid.... It's a low consentration but it's still a metal eating by-product. To see how much damadge over time has been done you might want to consider taking a sample of the old oil and sending it off for analysis. From what I've seen it's not very expensive and can get you geared up for a failure or relieved that your engine is running fine.

Good luck.

 

[Soundguy]

I wouldn't start it again without putting a mechanical oil pressure gauge in there.. once I saw pressure was good.. i'd change the sender.. then change the oil. I always change the oil in new-to-me tractors.. unless I helpe dthe previous owner do it.. etc.

soundguy

 

[RobJ]

Actually I would worry about it and take it serious. Put your gauge on it and see what it really is. Most of the senders close the circuit around 3-5 psi. Also the bad news is in all the engines I've rebuilt, I've never found an oil pump to be out of "spec". It's usually just a saftey precaution to replace them. IE a CYA, because if I rebuilt an engine and it failed and there is no oil pump on the repair list, the customer is going to be all over that. Usually it's the bearings. Then there is the flow .vs pressure thing.

Good Luck,
Rob

 

[honeycutt]

1st I would like to welcome you to TBN! I've gotten alot of help from everyone here. Ditto with everyone else. I had the same problem with my L175. Changed the oil sending unit for less than $10 which fixed the problem. But, I would also (as said in an earlier post) that if I wasn't there for the oil change from the previous owner I would go ahead and do it again to give me that warm and fuzzy. Less than $30 for oil, filter and sending unit, go for it.

 

[MLD]

Thank you all here at TBN for your help and opinions. Special thanks goes to Blagadan for sending me the B7100 Manual as a pdf it's great and will use it when I change oil, filter and sending unit.

My local dealer doesn't have the sending unit in fact all three store in the chain do not. I thought it would be something on the shelf . I found it In PA and they can ship it 3 days faster than the local guy.

I will be, with help, checking the oil pressure with a new gauge to be installed this evening. Will keep you posted on results.

MLD

 

[Soundguy]

If you knew what thread pitch it was.. it's like a napa store could have gotten you one off the shelf. They aren't much more than a grounding switch that opens at a set pressure.. etc..

soundguy