'07 CK20s with bad fuel solenoid

[DroppedAxle]

Hi All,

My '07 CK20s has a fuel solenoid that's acting up and is mostly stuck in the "off" position. I've removed it and was able to unstick it for a bit, but it's basically shot. It'll take a few days to get the part and we're due for another 8-12" of snow so I'm thinking of the following fix: Remove solenoid, cut an inch of so off the solenoid plunger, and reinstall. Run a straight wire from the manual off lever (right next to the solenoid) to the cockpit for shutting the thing down.

What do you guys think?

DA

 

[paulfun9]

I had one go bad on my old JD and simply disconnected it and ran a push/pull Morse cable to it. Worked so good I never bothered replacing the solenoid.

 

[DroppedAxle]

Thanks, PF9.

One this one, the solenoid returns to the "off" position (plunger extended) when disconnected. So I need to trim the plunger. Or remove the whole thing, but then I need to seal the opening somehow.

 

[paulfun9]

Mine was a simple disconnect of the solenoid and to hook the push/pull cable directly to the point where the solenoid was connected. The solenoid just sits there not connected to any thing.

Maybe a wire tie to keep the plunger where you want it.

If everything is accessible you could simply leave it connected and use mechanics wire to hold it in the position desired to run the machine. At end of use carefully undo wire or simply cut it to let it return to off position.

 

[DroppedAxle]

Ah, I see. Mine has a plunger that inserts into the fuel injector. if the plunger is retracted (power on), it turns on fuel to the injector; if it's extended (off, default) no fuel flows. The solenoid itself cannot be opened short of destroying it. So I cut 1/2" off the plunger and it now starts and runs fine. There's another unused linkage that overrides the solenoid for manual "off" -- i ran a cable to that so I can shut it down from the cab. Thanks.

 

[ritcheyvs]

Dropped: That should work fine.

When unpowered, the solenoid rod extends and forces the injection pump rack (which controls the amount of fuel injected) to the full aft/zero fuel position. With the rod retracted (or cut off) the rack is allowed to move normally to regulate fuel as needed to maintain the commanded RPM. The external manual fuel shutoff linkage also pushes the rack full aft to stop the engine. I believe some early models did not have the electric solenoid and they were fitted with a push/pull cable from the manual linkage to stop the engine from the seat. Also (and this causes confusion) the early solenoids were external and operated the manual stop linkage; for those, power was applied briefly from a timer relay to stop the engine (vs allowing it to run) when the key was switched off. On yours, a high current "pull" signal retracts the rod and then a much lower "hold"current keeps it retracted as long as the key switch is "on." The ground return path is through the engine block. The high "pull" current is supplied through a relay which is controlled by a timer in the display unit. The "hold" current comes directly from the key switch.

 

[DroppedAxle]

Thanks for the detailed info, Ritchey.

Hopefully the solenoid was bad (now that i clipped the rod off) and not the relay/controller... I guess I'll know soon enough.

 

[ritcheyvs]

I have not read about any actual failed stop solenoids on TBN, but that doesn't mean it can't happen. I have read of one solenoid which was replaced but it turned out it wasn't defective. A new solenoid lists for $81 from MIE and you'll need one regardless but at least you have a working tractor for immediate needs.

The stop solenoid should make a very distinct click (or clack) sound when the key is switched on and the solenoid retracts. If a new solenoid doesn't do the trick, check the voltages on the two wires that go to the solenoid. One should read 12v whenever the key is on and the other should jump to 12v for about a second when the key is turned on and then drop to zero. If the voltages don't check out, check your fuses.