John Deere 1070 Low oil pressure light

[scratchpad]

You are welcome. Sure it can. Thinned oil can reduce pressure. If you are getting a good amount black smoke at start, fuel is puddling at the injectors. Just about all tractors can throw black smoke at start up but it clears in a second. Black smoke is a condition of too much fuel. Here's what you can do: drain the oil making sure you have sufficient fuel in your tank. Once the oil is drained, put back your drain plug and let it sit for a couple 3 days. Go back and unplug it. If raw fuel comes out, then you know your problem is not combustion related and may merely be exacerbated by running. I would side with leaky injectors if this happens.

ill give that a shot before it goes back to the mechanic.

 

[TimberHole]

Just to give you a data point I rebuilt my 3 cylinder Yanmar in a JD 950 and my oil pressure runs around 55 psi with a little rpm. I got it hot enough about a week ago that the temp light came on and I still had 30 psi oil pressure at idle.

 

[TerryR]

**** near couldve bought a new tractor for what this is costing me.

Sorry you're having so much trouble with the 1070. But when you get it sorted you will have a better tractor than if you bought a new one, in my opinion. I have an 870, little brother to your 1070, that I bought new over 20 years ago. Reading lots of posts here I realize how much better it is than what's being sold now.

For example, I keep reading posts about having to stop several times a day to clean off the radiator when mowing. I just spent four days (well, short days) mowing two-foot high grass with three and four foot weeds mixed in, in very dry conditions. The grill was coated with dust and chaff when I finished, but the temp gauge never got more than a quarter of the way into the green area.

Other features I've found useful based on issues others have posted: No PTO brake to make it difficult to align the splines when hooking up the PTO shaft; No electric PTO clutch that's designed to break shear pins when trying to start a heavy attachment; Both brake pedals on the same side so it's easy to use them to help turn when working the field or offsetting the tendency to drift down the hill; No regens to interrupt whatever you are doing. Just to mention a few.

 

[scratchpad]

Just to give you a data point I rebuilt my 3 cylinder Yanmar in a JD 950 and my oil pressure runs around 55 psi with a little rpm. I got it hot enough about a week ago that the temp light came on and I still had 30 psi oil pressure at idle.

Good to know. Im gonna put a mechanical gauge back on. As of right now thats basically what this one is doing. I got it hot, 30-40 minutes of high rpm, dropped the rpms and the light comes on at idle. Shut the tractor down for 15 minutes and start it back up and no light, let it run for a bit with no light returning.

 

[scratchpad]

Sorry you're having so much trouble with the 1070. But when you get it sorted you will have a better tractor than if you bought a new one, in my opinion. I have an 870, little brother to your 1070, that I bought new over 20 years ago. Reading lots of posts here I realize how much better it is than what's being sold now.

For example, I keep reading posts about having to stop several times a day to clean off the radiator when mowing. I just spent four days (well, short days) mowing two-foot high grass with three and four foot weeds mixed in, in very dry conditions. The grill was coated with dust and chaff when I finished, but the temp gauge never got more than a quarter of the way into the green area.

Other features I've found useful based on issues others have posted: No PTO brake to make it difficult to align the splines when hooking up the PTO shaft; No electric PTO clutch that's designed to break shear pins when trying to start a heavy attachment; Both brake pedals on the same side so it's easy to use them to help turn when working the field or offsetting the tendency to drift down the hill; No regens to interrupt whatever you are doing. Just to mention a few.

I hear ya. Im at my wits end of this. Its been such a negative experience i think its time for it to go to a new owner. On the other hand i basically have a new tractor that a few little things need to be worked out.

 

[scratchpad]

You are welcome. Sure it can. Thinned oil can reduce pressure. If you are getting a good amount black smoke at start, fuel is puddling at the injectors. Just about all tractors can throw black smoke at start up but it clears in a second. Black smoke is a condition of too much fuel. Here's what you can do: drain the oil making sure you have sufficient fuel in your tank. Once the oil is drained, put back your drain plug and let it sit for a couple 3 days. Go back and unplug it. If raw fuel comes out, then you know your problem is not combustion related and may merely be exacerbated by running. I would side with leaky injectors if this happens.

Drained oil and let the tractor sit unplugged for a bit and then put plug back in.
Next day pulled drain plug and about 1/2 to 3/4 of a layer on the round oil drain pan was covered with fuel/oil. Guessing about 1/8 of a quart. Put Plug back in
Day after that same thing with same results.

From internet searching i came across a guy named thepumpguysc that comes recommended so i emailed him. Rather than try to sell me on him rebuilding my injector pump he tells me to try a few things out first. He tells me that the delivery valve holders sometimes work themselves loose and may need to be retorqued. So yesterday, i disconnect the steel supply line and sure as heck one of the nuts was loose so i retorqued them all. With the tractor running good and no weird smoking issues or otherwise thepumpguysc thinks the injector pump is ok. Thank you @thepumpguysc for your time. Ive emailed him back and forth multiple times and he always responds timely. I may still send him my pump and injectors for peace of mind anyways.

So, Today i pull the drain plug and only get about ten drops of fuel/oil. Couldve been reminants of before i retorqued that nut. I also pulled the new fuel pump and let it dangle to check if it was faulty. No leaks so i bolted it back up and filled the engine back up with oil. Ran the tractor for a while 30-40 minutes with a mix of mid-higher rpms and finally got the low oil pressure light when dropping to an idle at the end. I checked the dipstick and was able to get a good read finally. Let the tractor sit for 15 minutes and started it back up and no light. Did that a few times and no light. At this point im beginning to think the fuel mixing with the oil issue is resolved and this may be normal. Gonna get a mechanical gauge hooked up to make sure.

 

[TimberHole]

Low oil pressure at idle can also be caused by excess clearance in the bearings. One way to assess the bottom end of an old engine is to get it good and hot and see what the oil pressure is at idle. Did your mechanic record any dimensions during assembly?

 

[scratchpad]

Low oil pressure at idle can also be caused by excess clearance in the bearings. One way to assess the bottom end of an old engine is to get it good and hot and see what the oil pressure is at idle. Did your mechanic record any dimensions during assembly?

Mechanic swears everything is good inside. Even the original oil pump he left in there. I would have gladly paid for a new oil pump since he was rebuilding the motor. He didnt bother to ask. He has the tractor back in his hands. If he has to tear back into the motor its all on his dime.

Before he picked it up i put a mechanical gauge on and journaled exact rpms and pressure. Basically after a half hour of no load operating the oil pressure drops down to below 5 psi at idle. 50 psis at start up and 1200 rpms.

 

[TimberHole]

Mechanic swears everything is good inside.

What does this statement mean? Did he replace the main and rod bearings? I wouldn稚 call it an overhaul unless the bearings were replaced so I just assumed he did. Did he split the tractor???? The 950 requires the tractor be split to pull the crankshaft. Im assuming the 1070 is the same but I might be wrong. Do you know how the oil pressure was prior to the engine work? Why was it overhauled?

 

[scratchpad]

What does this statement mean? Did he replace the main and rod bearings? I wouldn稚 call it an overhaul unless the bearings were replaced so I just assumed he did. Did he split the tractor???? The 950 requires the tractor be split to pull the crankshaft. Im assuming the 1070 is the same but I might be wrong. Do you know how the oil pressure was prior to the engine work? Why was it overhauled?

He swears everything is within spec. Yes, bearings replaced, according to him. Yes, tractor was split and motor was pulled and fully taken apart. No on the oil pressure. Crankshaft broke and damaged some journals about 3 hours after i bought the tractor from my neighbor. I got a smokin deal :laughing:

I sourced a good block and crankshaft for it to be rebuilt