John Deere 750 rockshaft

[Native Texan]

I have a Deere 750 that sat for several years unused. The arms are not lifted when pulling back on the lift handle. I just downloaded the Deere manual but am not sure what different valves might cause this problem. What different items should I check?

 

[loggin]

I have a Deere 750 that sat for several years unused. The arms are not lifted when pulling back on the lift handle. I just downloaded the Deere manual but am not sure what different valves might cause this problem. What different items should I check?

Welcome to the forum!

First off , have you checked the basics? Condition and level of hydraulic fluid? Replaced filters and cleaned the hydraulic screen if it has one? Does the power steering work?

We need to know what has been done already in order to further the process of diagnosing.

 

[Native Texan]

There is no power steering. I have loosened the banjo fitting from at the rockshaft and there is lot of fluid pressure. I don't know how to attach a pressure gauge to check the exact pressure. The stop valve threaded shaft is broken but I believe it hasn't been moved since it worked in the past. There is zero movement of the piston. My guess is there is some valve open in the rockshaft piston cover that should be closed. I pulled the rockshaft control valve off and the piston that is moved by the rockshaft control quadrant moves freely but I didn't know how to check anything else in that system. My first guess is that I need to check out the piston in the other end of the rockshaft control to see if it is stuck open.

 

[5030]

What I would do is pull the bleed off valve that controls the fluid movement to the rockshaft piston first. I bet it's either seized up or clogged up.

 

[Native Texan]

I just pulled the endcaps (cannot find the page that describes them with the correct terms) off of the rockshaft control. I found that the piston (maybe that is the right term) is stuck. It does not move. I ran out of time but plan to work on it the next dry day here in Fort Worth. Any suggestions about how to free it up?