how to test John Deere 2305 PTO Solenoid

[RickB]

Answered in post #11.

 

[gtrgarden1]

Answered in post #11.

Yes, thanks.
And I don't mean to be a smarty-pants by saying this, but I was hoping for a more detailed description of how that part moves or reacts.
Maybe some YouTuber out there has a video of that part in action?
I do appreciate your input.

 

[LouNY]

Depending on the solenoid most will have spring for a positive travel in one direction, the fail position, open or closed depending on application and desired off position.
When energized the winding "coil" created a magnetic field which is strongest inside the center of the winding.
This magnetic force is what will pull the actuator in the solenoid.
Therefor when energized you often will find a magnetic pull around the coil area of the solenoid.
Some times when activated with your hand on the solenoid you will feel and hear a clunk as it moves the activated device.
How ever with high pressure hydraulics the valve and seat are often so small you will not hear or feel it move.
With a meter capable of measuring DC current you could series your meter into the power loop.
With your coil reading 9 ohms you should have a current draw of around 1.3 to 1.6 amps.
If you have it removed from your tractor applying and removing power with an air line connected to the inlet side should turn the air on or off.

 

[WranglerX]

Umm... IT's just a coil of wire, it does not know if there is a plunger in solenoid or not, All it does when power applied is it creates a magnetic field.... Real test is put a OHM meter across terminals... IF you have a reading (probably a few hundred ohms) coil is probably good, If you get a infinite reading coil probably has "open circuit" and is defective... About half the information posted here about it self destruction is pure hogwash.... Been around relays and solenoids and other electrical stuff for years and never see a solenoid self destruct when proper voltage is applied....

Dale

 

[WranglerX]

I appreciate the advice about the coil. But, let's assume that IF the coil is good, what I'm really wanting some input on is how the "shaft/valve" should react when it's energized by the coil.
Maybe there is a more proper name for it. What I'm calling the "shaft/valve" is the metal parts that inserts into the black plastic coil.
View attachment 627935

Here's a photo of a new complete Solenoid showing the coil and shaft separated...
View attachment 627940

Plunger... (also may be called armature).
Dale

 

[LouNY]

I appreciate the advice about the coil. But, let's assume that IF the coil is good, what I'm really wanting some input on is how the "shaft/valve" should react when it's energized by the coil.
Maybe there is a more proper name for it. What I'm calling the "shaft/valve" is the metal parts that inserts into the black plastic coil.
View attachment 627935

Here's a photo of a new complete Solenoid showing the coil and shaft separated...
View attachment 627940

The piece that you are calling the shaft is composed of more then one piece.
If you assemble those pieces (set the coil on the armature and secure it with the supplied nut)
when you apply 12 vdc to the coil you will see the inner piece move, that is actually a valve to allow hydraulic fluid
under pressure to flow to the pto clutch, when de energized it will allow fluid to return releasing the pto clutch.
Some solenoids will not move unless there is external pressure to drive it, this perticular one looks like it would.

 

[RickB]

It is worth noting that some PTO solenoids are PWM solenoids and therefore are sensitive to a full 12 volts. I don’t know if yours would fall in that category, but it would be worth knowing before applying 12 volts from an outside source for testing purposes. If the circuit is powered by any kind of controller or computer I would be cautious.

 

[gtrgarden1]

Eurika... I fixed it !!!
The "piston" that moves inside the metal shaft of the Solenoid was stuck.
Here are some details that I hope will help the next person who may be trying to troubleshoot and repair this issue.

I found these photos posted by "Newbie 2" at tractorforum.com...
I'm so glad Newbie posted the photos because it was the breakthrough I needed in understanding how the solenoid operates.


In the first photo, the arrow points to the "piston" that rides inside the outer sleeve. You should be able to move the piston inward. In the second photo, Newbie is using a pen to push the piston inward. It will spring back outward on it's own, if operating as it should.
In my solenoid, the piston was stuck and would not move inward. To remedy that, I used the blunt end of a drill bit that was the right size to insert inside the outer sleeve and rest solidly on the piston. A few light taps on the drill bit with a hammer was all it took to free the piston. Once freed, it was easy to push the piston in and it would spring back.
I re-installed the solenoid in the tractor and the PTO was operating again!

Big thanks to Newbie for the photos, and to everyone on this forum who contributed to the thread. I'm NOT a mechanic, but I always try to see if I can make repairs when a problem arises. Having forums like this to search for ideas and get advice is a huge help.

 

[RickB]

Great news! Thanks for posting your results.