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Discussion Starter #1
After replacing the rest of power steering hoses on my 4020PS, I installed the sleeve hitch and mounted the tiller. It’s the end of May and still too wet to till the garden. With everything connected and the tiller raised, I engaged the rear PTO to test the tiller; the engine nearly quit. I tried again with same results so pushed it back inside to think about it. After letting it sit overnight, I checked whether it was still stuck or blocked (it was) so I tried reverse. Kapow! Something popped and oil shot straight back (7’ 4”). The tiller’s hydraulic motor housing cracked horizontally across the back side below the hose fittings. Model: H70, serial no: 0031154, part no: C24695. Repair or replace?
 

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I would say you need a new hydraulic motor. My question is, was the motor froze up or is there a deadhead somewhere in the PTO system or is the chain drive froze up ? If you loop the hose on the PTO valve does everything work when putting the PTO in fwd/rev ?

:dunno:
 

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Discussion Starter #3
Did you ever wake up with a sort of panic-stricken feeling, maybe asking yourself, “Did I remember to…?” That happened to me this morning and the question was, “Did I remember to remove that piece of paper shop towel from the ‘valve out to heat exchanger’ hose before putting it back together?”

I had removed that hose (the upper one) where it connects to the heat exchanger to give myself more room to remove/replace the power steering hoses. To absorb oil dripping from the fitting and hose, I loosely stuffed a piece of shop towel in each. Thinking back, I was almost certain I’d removed one and was starting to think I’d forgotten the other. I connected the PTO output and input hoses to confirm the problem was with the tractor. Doggone.

I studied the parts manual. I believe oil flows through the hydraulic system as follows:
Oil reservoir
Hydraulic pump
Power steering regulator
Rear PTO
Control valve
- Hydraulic lift and back
- Hydraulic motor and back
Shop towel
Heat exchanger
Oil filter
Oil reservoir

If that’s correct, then I suspect the shop towel is lodged in the heat exchanger. I drained the system, removed the hose where I introduced the problem and removed the oil filter. No evidence of paper shop towel or fragments.

Here are the symptoms… I’ve run the engine only a few minutes between reassembly and destroying the tiller’s motor housing and just long enough afterwards to determine the problem was with the tractor. Forward and reverse work, low and high range work, raising and lowering the lift work, power steering works but turned hard intermittently twice. Engaging the rear PTO one direction causes the engine to bog down (would quit if I let it); tried it the other direction only once and very briefly.

So given what I did, the way the system works, and the symptoms, what do you think? As always, help is appreciated. Thanks.
 

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Assuming I have understood your post correctly, you say the tractor acts normally until you move the PTO valve in either direction, and then it bogs. Oil is always flowing through the PTO valve when the engine is running. When you put the PTO in FWD or REV, you are diverting the oil flow through a devise. If I have read this right, it seems the blockage is in the PTO valve, quik-connector, or hose. One of the quik-connectors could be stuck.

:fing32:
 

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Discussion Starter #5
Thanks, RestMyCase. That's a better theory. In that case, I guess it would be the left side (my PTO valve is an HP34). As I recall forward flow is left-to-right, which allowed no oil to the tiller. Right-to-left reverse flow broke the housing. Suggestions on trouble-shooting the valve or quick-connector?
 

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I would start by removing the quik-connectors and examing them. Then I would loop the PTO valve with a hose eliminating the quik-connectors. Make sure the hose(s) you select are not plugged or damaged internally. You can also test the PTO valve by removing the main lines from the tractor hydraulic system and connecting them with a straight coupler fitting. If the problem is back there, these tests should isolate it. Use exreme caution around the system when testing.

:dunno:
 

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Discussion Starter #7
Removed quick connects and hoses, ensured hoses were clear, reassembled using straight fitting instead of quick connects, and tested flow both directions successfully.
 
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