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Discussion Starter · #1 ·
I have a problem with the terrain tracer system on my Tr86 It just all of a sudden won't level the head when lowering the feeder house. It tilted to the left and won't move at all. We checked the switches and diodes etc, but no luck. The top valve on the valve stack has 2 hoses coming off the side of it to the feeder house tilt cylinders. The back hose has pressure on it all the time. Seems to be something inside the valve sticking. I've been having trouble lately when lowering the header it tilts to the left, even with the electric header control turned off. Got to be hydraulic problem.
 

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Discussion Starter · #2 ·
The guy helping me check it out used to work with me at a CIH New Holland dealership. He said the solenoids on the top valve are getting power when raising and lowering the head when they shouldn't be. Found one bad diode, but still won't level. He thought there is also a hydraulic problem. I had to put a new pump on this combine a few weeks ago, and ever since then the steering is jerky and almost locks up if you try to turn while raising the head, and the unload auger moves in jerks unless you turn the header control off.
 

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Before you take the valve apart check to see if by chance the the valve somehow has power even though it should not. A fault in the harness or relays might power it up even though it should not be.
 

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Discussion Starter · #4 ·
Well the Terrain Tracer isssue is fixed, turned out to be a broken plastic poppet in the tilt valve on the valve stack.
As far as the pump, I didn't have the screen out but the hose is in good shape and had new orings on all the fittings. The pump being below the tank makes me think it would be hard to get air in the pump. But since I got the beans done today I may drain the hydraulic oil and check the screen and the dealer told me to take the pump in to be checked over. I also have a rattle in the separator drive clutch when it is engaged that needs to be checked out. Maybe a rough bearing in the clutch assembly or something. The noise goes away when I disengage the clutch.
The diodes all checked out OK on my tester and the header worked good all day.
Thanks for the replies, wtw.
 

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First thing I would check in regard to your steering issue and jerky movement of the unload auger is for a leak on the suction side of the hydraulic pump. Sure sounds like air in the system. Did you clean or check the suction strainer in the reservoir when your replaced the pump? Suction hose in good shape and clamps tight? The issue of the terrain tracer solenoids getting power when they should not sounds like diode issues.
 

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Glad you found your problem with the terrain tracer. A quick way to determine if the problem is at the head or with the combine is to disconnect the plug at the head for the terrain tracer. Leave the header control plug connected. Turn the header control switch on. If the head does not tilt when lowering the problem is with the head most likely a bad switch. If the head continues to tilt with the plug disconnected the problem is usually what you found, a bad poppet. It could also be a broken centering spring under the large caps on the same valve.

Turning the header control off does not stop the head from tilting while lowering the head when there is a problem with the terrain tracer switches.

If you look at the solenoids on the header lift valve you will see two wires attached to each. One comes from the raise/lower switch in the cab and the other goes to the header control switches through the plug at the head.

Remember when the head is up in the air the lowering switch for the header control is activated. Now with the header control switch in the cab off pushing the header raise/lower switch to lower the head sends current to the header lift valve lowering solenoid.

Since there are two wires attached to the solenoids the current continues to the header plug and then to the lowering switch for the header control. Since the lowering header control switch is activated current passes through the switch and back through the wire that would normally be the power wire when the header control switch is on.

Now if you look at the two plugs at the header you will see one wire goes from the header control plug to the terrain tracer plug. Normally this is the power wire for both systems. In the above scenario when the header control wire is energized the terrain tracer system is also energized through this wire. If one of the terrain tracer switches is stuck it will complete the circuit in the terrain tracer switch and send power back up to the terrain tracer valve and the head will tilt while being lowered.
 

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Discussion Starter · #8 ·
Well I had the pump checked out at the dealer and they found a scored flow divider spool in the pump. I guess they put in a new one and put it back together. I got it back on tonight and it seems to work better.
 
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