Deere Dial a matic Problem

Mitch D · Oct 30, 2013

Older 915 flex head on our 9500, two years ago it worked great, last year it started to bounce instead of gliding smooth like it should so put new heigth sensor on the head and still did it part time. Now this year it does it prolly 90% of the time, Took sensor off and moved it manually and the head went up and down good and stops as soon as you move it but when you put it back on the head it bounces. Anyone else had a problem like this?? JD dealer dont have much advice on it.
Thanks Mitch

4435 · Oct 30, 2013

IF! it has the big box on the end take it off. Next make certain the plastic wiper arm and hole it goes thru are not nasty sloppy. Check the actuating rod that runs end to end that there is nothing used up or broken. Then pencil eraser the circuit board really well.

After I learned the eraser trick I fished a junker out and used that trick. Now running it.

Tom

Heat Houser · Oct 30, 2013

Don't know about a 9500 but most combines have a rate of drop adjustment. Choking it down allows the solenoid to shut off the flow to the lift cylinders to prevent overstroke (down too far causing hunting).

Do you have an accumulator in the lift circuit? If you do and it is flat, (lost its nitrogen charge) this will also cause overstroke (hunting)

My 6620 has rate of drop adjustment and accumulator. It will hunt if you forget to open the valve to put the accumulator into the lift circuit. Same with a flat accumulator.

Mitch D · Oct 31, 2013

Yep the accumulator is one turn open as it says to be for dial a matic flex head work. We slowed down the rate of drop and it seemed to help just here in the yard but that just seemes like a band aid fix?

Heat Houser · Oct 31, 2013

Has your accumulator lost its nitrogen charge?
There was a test for charge, think is was lower head to the ground, hold the lever to be sure all the stored hyd oil is pushed back out, close the valve and raise the head. Measure how high the cutter bar was off of the ground, open the valve and measure how much the head would settle.

Sorry but don't know if this is still a valid test for a 9500...it is for my 6620. Don't remember how much it should settle however.

If it doesn't settle hardly at all, it means that your accumulator has problems and is likely full of oil and does not have a charge. If it is a rubber diaphragm type it is likely the diaphragm is ruptured.

This happened on my 6620 and replaced it with a piston type as the original is a welded non repairable...

4435 · Nov 2, 2013

Mitch, When the accumulator on my machine went bad I got a new piston type and a gauge/charging set here.accumulators.com for less money than a new from Deere. I have access to high pressure air and use that but a guy can get a nitrogen tank for not a lot of money. Tom

Deere Dial a matic Problem

Mitch D

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Heat Houser

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Mitch D

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