4720 PTO issue??? Help!!!
- Thread starter bill boyce
- Start date
OP
bill boyce
New member
Update: I talked with previous owner and he suggested that I replace hydraulic fluid and filter. I thought he did this before I bought it in Dec. So I just replaced fluid and filter. I cleaned both transmission screens neither were dirty. Fluid was dark almost black in color. Put new filter and fluid in. Still did the same thing after mowing for about 10 min. This is so frustrating!!!!! I think I will bypass the seat switch. If that doesn't work only thing left to do is to tackle pto pump. I don't think it has the e-pto option.
OP
bill boyce
New member
There were a few metal shavings in the transmission screen but none in the inline screen. Overall both screens were very clean to me. Any ideas on fix with metal floating around? Only thing I see is to take off the pto pump and see whats in it.
Spanner
Veteran Member
I believe Joe has supplied you a copy of the manual. Have you read it yet?
Why bypass the seat switch? What diagnostic procedure has led you to this decision?
The dark fluid is perhaps a clue.
Minor shavings in the screen are not abnormal.
Why bypass the seat switch? What diagnostic procedure has led you to this decision?
The dark fluid is perhaps a clue.
Minor shavings in the screen are not abnormal.
OP
bill boyce
New member
Yes I have read both the owners manual and the tech manual. There is nothing in there that specifically states my problem. I am just trying to narrow down why it is doing this. The dark fluid tells me it was time for new fluid.
Spanner
Veteran Member
So you need to diagnose the problem when it is faulting. That is, when your tractor has been working and the PTO won't re-engage.
Under those conditions you need to verify power to the PTO solenoid. A simple procedure with a circuit tester probe/lamp.
When the fault occurs place someone in the seat to operate the PTO switch on-command for you.
Disconnect the PTO Solenoid at the weather-pak connector. Insert probes into both terminals of the power cable connector and operate the PTO switch. (Soldier B's job). Your tester should light-up. Or your VOM should show voltage present.
Work forwards or backwards from there.
Read the test for the PTO switch which requires accessing the rear of the switch etc.
I agree - Dark oil is ominous.
:wrench:
Under those conditions you need to verify power to the PTO solenoid. A simple procedure with a circuit tester probe/lamp.
When the fault occurs place someone in the seat to operate the PTO switch on-command for you.
Disconnect the PTO Solenoid at the weather-pak connector. Insert probes into both terminals of the power cable connector and operate the PTO switch. (Soldier B's job). Your tester should light-up. Or your VOM should show voltage present.
Work forwards or backwards from there.
Read the test for the PTO switch which requires accessing the rear of the switch etc.
I agree - Dark oil is ominous.
:wrench:
Spanner
Veteran Member
You will be testing the connector to the two wires coming off the solenoid (Item 16) shown:
Just asking: How comfortable are you with Electrical & Hydraulic work?
The dark oil could indicate 'overheated' hydraulics or just very old oil. You did say the oil was supposedly changed prior to purchase?
Refilling with JD Hygard is recommended.
On the overheating concept - I wonder if components in the PTO valve are 'dirty' now, or sticking when heated, thus preventing the valve from operating correctly?
Just asking: How comfortable are you with Electrical & Hydraulic work?
The dark oil could indicate 'overheated' hydraulics or just very old oil. You did say the oil was supposedly changed prior to purchase?
Refilling with JD Hygard is recommended.
On the overheating concept - I wonder if components in the PTO valve are 'dirty' now, or sticking when heated, thus preventing the valve from operating correctly?
OP
bill boyce
New member
I will try to do the test. I have already replaced both the solenoid and armature with new ones. I tested old components and they had proper ohms. I am pretty sure looking at that oil it was not changed anytime soon nor the filter. I agree with the possibility of the PTO valve dirty or sticking when heated.
Spanner
Veteran Member
Replacing the Solenoid and the Coil (Armature) may not have been necessary. That's why you need to prove the power supply to the connector first.
Edit to add: If the power is present at the connector when the machine is at the hot operating temperature needed for previous fails, and you have a new coil and solenoid then you go forward into the valve block I think.
Keen to hear your progress Bill.
:wrench:
Edit to add: If the power is present at the connector when the machine is at the hot operating temperature needed for previous fails, and you have a new coil and solenoid then you go forward into the valve block I think.
Keen to hear your progress Bill.
:wrench: