Cold starting MF 860 then no move

[fdt860]

Hello,
I had to move the 860 to do some work in the shed, (I needed space), weather was clear and freezing (around 30F), so she sat outside for 2 days under the sun and the stars.
When I wanted to put the combine back in the shed, I had to fight dead batteries. I pushed on the "start" button. (She is a V8). She then started, but very quick, like from 0 to 1200 rpm in 1s. It was about 28F.
I waited few minutes, then I wanted to back it up : No move at all. Like if the "clutch" pedal was depressed.
I stopped it, checked for oil and leaks: Oil level was full, but I found a leak at the filter seal. (on top of the engine compartment). I changed filter and seal, checked for oil in the pipe going to the pump: All good.
The combine would not move at all, even after letting it at 1/3 forward for 5 min at idle.
I tought that I had stripped the charge pump input shaft by having it started too fast when cold. I removed the pump, no signs of damages.
Then I put another spare pump from a Deere 5400 chopper that I had (also a Sauer Sunsrand pump).
Doing it, I found that the hose feeding the pump has a loose end fitting right at the pump connection. It does not leak however and must have been like this for years. Pump is full of oil and pipes are full of oils.


I should have checked charge pump pressure first, I will do it tomorrow.
Do you think the hose connector is sufficient to have 0 operation at all?
Do you ever had a similar experience and what was the route cause?
Lastly, I am thinking about putting the entire JD5400 pump if I cannot figure it out. Does someone knows the displacement of both pumps?

Thanks!

Frédéric

 

[lugnuts2030]

Hello,
I had to move the 860 to do some work in the shed, (I needed space), weather was clear and freezing (around 30F), so she sat outside for 2 days under the sun and the stars.
When I wanted to put the combine back in the shed, I had to fight dead batteries. I pushed on the "start" button. (She is a V8). She then started, but very quick, like from 0 to 1200 rpm in 1s. It was about 28F.
I waited few minutes, then I wanted to back it up : No move at all. Like if the "clutch" pedal was depressed.
I stopped it, checked for oil and leaks: Oil level was full, but I found a leak at the filter seal. (on top of the engine compartment). I changed filter and seal, checked for oil in the pipe going to the pump: All good.
The combine would not move at all, even after letting it at 1/3 forward for 5 min at idle.
I tought that I had stripped the charge pump input shaft by having it started too fast when cold. I removed the pump, no signs of damages.
Then I put another spare pump from a Deere 5400 chopper that I had (also a Sauer Sunsrand pump).
Doing it, I found that the hose feeding the pump has a loose end fitting right at the pump connection. It does not leak however and must have been like this for years. Pump is full of oil and pipes are full of oils.


I should have checked charge pump pressure first, I will do it tomorrow.
Do you think the hose connector is sufficient to have 0 operation at all?
Do you ever had a similar experience and what was the route cause?
Lastly, I am thinking about putting the entire JD5400 pump if I cannot figure it out. Does someone knows the displacement of both pumps?

Thanks!

Frédéric

I had it happen to a 760, same hydo as 860. There are 2 valves that go into opposing sides of the pump and they stuck. This will cause no movement. One valve for forward, and one for reverse. I took them out and was only able to free 1 up, then I could go forward or reverse, depending where the working one was. I had to take a valve out of a parts machine. It was a easy fix, once I found the valves. I believe there is a oil line over top of the valves.

 

[wore out]

Hello,
I had to move the 860 to do some work in the shed, (I needed space), weather was clear and freezing (around 30F), so she sat outside for 2 days under the sun and the stars.
When I wanted to put the combine back in the shed, I had to fight dead batteries. I pushed on the "start" button. (She is a V8). She then started, but very quick, like from 0 to 1200 rpm in 1s. It was about 28F.
I waited few minutes, then I wanted to back it up : No move at all. Like if the "clutch" pedal was depressed.
I stopped it, checked for oil and leaks: Oil level was full, but I found a leak at the filter seal. (on top of the engine compartment). I changed filter and seal, checked for oil in the pipe going to the pump: All good.
The combine would not move at all, even after letting it at 1/3 forward for 5 min at idle.
I tought that I had stripped the charge pump input shaft by having it started too fast when cold. I removed the pump, no signs of damages.
Then I put another spare pump from a Deere 5400 chopper that I had (also a Sauer Sunsrand pump).
Doing it, I found that the hose feeding the pump has a loose end fitting right at the pump connection. It does not leak however and must have been like this for years. Pump is full of oil and pipes are full of oils.


I should have checked charge pump pressure first, I will do it tomorrow.
Do you think the hose connector is sufficient to have 0 operation at all?
Do you ever had a similar experience and what was the route cause?
Lastly, I am thinking about putting the entire JD5400 pump if I cannot figure it out. Does someone knows the displacement of both pumps?

Thanks!

Frédéric

Hydros are a complex mechanism with LOTS of things that can go wrong.

MANY years ago I went to a field near the farm and combined a sample of wheat for a moisture test with my IH 503.

It was a nice fall day and the machine worked perfectly.

I shut it down and my B-I-L picked me up and we took the sample of wheat to town for a moisture test.

The wheat was too wet to harvest and we went to retrieve the combine when we got back to the farm and it wouldn't move.

It turned out that that a pin had fallen out inside the hydro linking the external speed control linkage to the internal valve mechanism!

There was no sign of the cotter pin that should have retained the linkage pin.

The machine was 10 or 12 years old at the time, WHY would the pin have fallen out at that particular time?

NOT to say that's what happened to yours, but it's an example of a SIMPLE thing that disabled a complex mechanism!

 

[fdt860]

Thank you for the insight. I checked the linkage and that the servo valve was not stuck. All was fine.
I checked that the pump is turning and that the priming pump was spinning.
When I move the control forward or reverse, it sounds like the relief valves on the motor are full open, even so I have 0 pressure. I have a good stream of oil flow coming from them.
Lugnuts, are you sure that the valves you are talking about were on the pump?
In the pump, there are 2 check valves and maybe they are part of the problem as well. I have removed the charge pump but have not pull them out. If you said "it was an easy fix", the valves you are talking about must be the motor relief valves. Charge pump check valves are "not an easy fix", altought not too bad.

 

[fdt860]

I got it working again: removed the hydro pump ,ready to swap with the Deere 5400 pump. Then I read the plate on both pumps and I figured out my mistake: 5400 pump is cw,and mf is ccw.
I have disassembled the 5400 charge pump and converted it for ccw rotation (needs to swap drive shaft with idler shaft, and reassembled so the pump inlet is on the opposite side of the pump control valve). I double checked the motor relief valves and shuttle valve and found that around 11pm on wednesday, I had lost a ball in one of the relief valve. I have also air tested the pump with charge pump removed. It did not sound too bad.
This afternoon , i reassembled it, primed it using pressure in the oil tank, and it worked perfectly. Looking at it again, problem was obvious, if charge pump is defective, you have no oil motion in the tank. With a good pump,oil motion can be seen from the oil fill plug.
My mistake was to put the 5400 chopper charge pump with the fittings backward and think it is just one way or the other based on space available.

I also had an issue on the pump inlet hose, and an oil inlet filter leak. Concerting the 5400 pump that used to run cw in the ccw motion removes all olay on the pump driveshaft,

 

[fdt860]

There is a guy on yourybe "western repair",that shows how to lap pistons and pump swash plate. Very interesting stuff. He is a goid guy that does mistakes and learn. I feel a little bit the same as I surely foes mistakes!