Ingersoll 4018 Holding valve

[dirtdiggerdug]

I own a Ingersoll 4018 tractor. I have been mowing for years on hilly terrain and never had a problem till the other day. I was descending a hill and all of a sudden it starting free wheeling. I have tried descending shorter slopes to try and duplicate the action, but it seems to be working okay. I believe it to be a problem with the holding valve which is part of the travel control valve unit. I guess it's possible a piece of something got stuck in there and has since flushed itself out. If it was an O ring or some other problem it would occur even on shorter slopes. For now I'm staying off the longer slopes, don't want to go on another scary ride. Any input appreciated. Thanks in advance. Doug

 

[hydriv]

When was the last time that you followed the procedure outlined in the Operator's Manual and changed out the hydraulic oil? What oil are you using? It is very possible that a small bit of particulate interfered with the operation of a pilot in the holding valve and has now moved on. But you should not rely 100 percent on the holding valve without knowledge on how to control your tractor without that feature. You must keep the tractor in Lo Range whenever descending a steep grade and you must keep the engine running at 3/4 throttle or higher. If you feel the tractor running away, then pull the travel lever downward to the ****** position. This is a small area on either side of NEUTRAL. If you do not get enough control on the Forward side of Neutral in the ****** zone, then pull the lever past Neutral into the Reverse side of the ****** Zone. If the holding valve is working properly, then you will not be able to practice this procedure but if you memorize it and are prepared to use the procedure, then it just may save your butt at some point in the future.

 

[dirtdiggerdug]

When was the last time that you followed the procedure outlined in the Operator's Manual and changed out the hydraulic oil? What oil are you using? It is very possible that a small bit of particulate interfered with the operation of a pilot in the holding valve and has now moved on. But you should not rely 100 percent on the holding valve without knowledge on how to control your tractor without that feature. You must keep the tractor in Lo Range whenever descending a steep grade and you must keep the engine running at 3/4 throttle or higher. If you feel the tractor running away, then pull the travel lever downward to the ****** position. This is a small area on either side of NEUTRAL. If you do not get enough control on the Forward side of Neutral in the ****** zone, then pull the lever past Neutral into the Reverse side of the ****** Zone. If the holding valve is working properly, then you will not be able to practice this procedure but if you memorize it and are prepared to use the procedure, then it just may save your butt at some point in the future.

I use Rotella T 15w40. It calls for Ingersol 20w40 but it is a little pricey and I have read were other people used Rotella. I change my fluids as recommend in the manual. I always cut in low range even on the level and at full throttle. I'm going to try cutting the hill again tomorrow. Maybe I bumped the travel lever into neutral or did some other operator error thing and maybe that's why it happened. Thanks for the input. Some good points. Doug