Rollback Fast Idle

[Tim Brown]

Hello guys, I sold an 06 International Jerr-dan Rustler rollback to a fellow a couple years ago, he called saying the truck stopped idling up when he engages the winch. it does on the other functions, just not for winching. Any suggestions?

[GRUMPS The Towman]

Being a rollback, I assume that the fast idle engages when the p.t.o. is on, Right? With that said, if it seems to "idle down" when only the winch is run, I feel that there is possibly a blockage in the hydraulic system related to the winch somewhere or possibly the winch itself has failed internally. Be it the hydraulic drive motor or the gear drive itself.

Or is it an alternating fast idle system that only calls for more idle speed when a hydraulic valve is opened? I dont see any of these systems on rollbacks around here so I am Assuming it is not. That system is more suited for likes of bucket or boom truck systems.

Of course this is just an educated guess on my part. Without actually seeing it in operation it is difficult to say for sure. 

[Tim Brown]

Pretty sure it only idles up when its under a load like when a lever is engaged. my first thought is it must have a relay going to a solenoid but he doesn't see any switches on the linkage that would close a circuit so now im puzzled. no wiring on the valve body . there is a solenoid and when he jumps it then it does speed up the idle but just not sure because that solenoid covers the other levers too. They all work fine. it's all very puzzling especially since i dont have the truck here to see it. The winch works fine.

Edited September 11, 2020 by Tim Brown

[GRUMPS The Towman]

If it only idles up under load then it is a alternating system. there is a pressure switch somewhere on the feed hydraulic line that "feels" for an increase in pressure, The switch closes under pressure and sends signal to the truck to increase idle. Usually when they go bad none of the features will fast idle the truck. I suppose it is possible if the pressure switch is getting weak, the winch is not drawing enough pressure to trip the switch.

[rreschran]

With the I/H being 14-year's old, you can bet it's probably seen its share of use and abuse. These trouble-shooting events can be real head scratchers for sure and Grumps might be headed in the right direction suggesting a pressure problem? Does you system have a filter? If yes ... has it been replaced? Also, consider draining and changing what might be crudded hydraulic fluid if its never had the fluid checked or changed. A more progressed problem with old PTO units could be the pilot bearing on the PTO's entry shaft coming off the motor.       R.

[Tim Brown]

Thanks for the input, actually everything except the winch function does idle up the motor just fine. there is a solenoid on back of the valve body though and he says when he cross wires it then it does raise the idle with the winch lever being moved. he mentioned that he changed the hoses going to the winch motor a month ago too so maybe some debris got into the system , or air.