3-Point Hitch Pulsating 3 point hitch

RegL · Aug 6, 2005

I have one of the now defunct Rhino Internationals that has developed a problem. With a heavy attachment raised on the 3ph, the hydraulics pulsate about once per second and the whole tractor jumps every time it does it. Also, with the tractor shut off, the 3ph bleeds down very quickly. I'm selling the tractor and don't want to stick someone with a big repair bill so looking for clues to what the trouble might be. Thanks.

greg_g · Aug 6, 2005

Ordinarily - assuming no visible leaks anywhere - TPH leakdown suggests the lift piston seal, involving nothing more complicated than an O-ring/wiper replacement. Messy, but not difficult.

But the one second "jerking" symptom would probably have me looking at the relief valve first.

//greg//

rsatter22 · Aug 8, 2005

I've got a Shennui with the same problem that I haven't taken time to repair but I had a response from Mike Stuart (Mike was one of the first Chinese tractor gurus) on the old CTOA board about this.
Quote "Your problem is inside the lift cover. Remove the seat, remove the top plate (off the lift housing). Start the tractor, raise the lift (with weight on it), you'll see some bubbles or oil squirting out around a plug on top of a rectangular block. Under this plug, is an o-ring that needs to be replaced. Be sure to let the lift down and turn off the tractor before unscrewing the plug, or you'll get an oil shower." End of quote.
If I'm not mistaken the Rhino and Shennui had many similarities in their designs so this might be worth checking. I need to get around to this yet myself.
Rick

Soundguy · Aug 8, 2005

In general.. refering to 3ph lift systems .. if you have a bad enough leak in the system fo rthe lift to visibly come down fast.. than the 'regeneration' can cause the jump. As the others mentioned..could be cyl pcking.. or things like sticking valves.. good luck.

Soundguy