Hitch won't hold tiller or brush hog up very long

[donpeak]

I have to hold lever up half of the time on Zen Hoh 1500 (Kubota 175) . One repair guy thought it was leaking some how, but no oil shows up. It holds for about 20 seconds and then slowly goes down. Not fun unless your're mowing or tilling. Any thoughts? Front loader holds bucket up well. Just rear 3 pt. "leaks down"
Thanks,
don peak

[k0ua]

Well I am no hydraulic expert, but it sounds to me like you have a leak in the 3pt control valve or the hydraulic cylinder. There would be no drips external to the tractor as the leak is internal. In other words the leaked oil goes back into the "tank" which is the chassis of the tractor.. sounds like a tear down and inspection to me.

James K0UA

[J_J]

You probably have a worn 3pt piston seals.

There is only two places for the fluid to go.

Leaking piston seals and worn 3pt valve spool. Can you hold the lever to raise position and make the relief go off?

[Professor Marvel]

agree with these opinions. Happenned to me. Towed it to dealer. All fixed now.

[Leejohn]

There are 2 o rings between the 3pt valve and rockshaft housing don't forget to look at them.