M7060 3PT return line blows

[Al38kit]

There is a small hydraulic return line just behind the cab.
It is hooked to a T fitting and then the two lines connect to the hydraulic cylinders that lift the 3 point hitch.

Anyone else have issue with these lines coming off the T fitting?

I wired them on last time and tonight they both blew off when I lifted the big mower.

Ideas?

 

[Russell King]

I assume you are talking about the air vent line shown highlighted below. I assume the cylinders are single acting in the upward direction under pressure and gravity downward. That would mean that no hydraulic fluid should on that side of the cylinder. Therefore, I think you have a leaking seal on one or both of the cylinders that fills that upper side of the cylinder and when you lift the three point hitch it forces the fluid into that relief hose and blows it off the fitting.

 

[Al38kit]

I assume you are talking about the air vent line shown highlighted below. I assume the cylinders are single acting in the upward direction under pressure and gravity downward. That would mean that no hydraulic fluid should on that side of the cylinder. Therefore, I think you have a leaking seal on one or both of the cylinders that fills that upper side of the cylinder and when you lift the three point hitch it forces the fluid into that relief hose and blows it off the fitting.

View attachment 175155

Thank you for the insight as to how this should work.

It explains things very well...I'll check the cylinders individually tomorrow.

That makes good sense as I could not figure out why the return line (which it's not) was made that way.

I'll plan to buy cylinder rebuild kits...anyone know how difficult it is to do these small cylinders?

Thanks again.

 

[North Idaho Wolfman]

Yep @Russell King nailed it.