Hi there,

Our C4000 has a steering creep problem, and I need fresh advice:

The RHS steering cylinder was damaged (shaft bent) after an hydraulic pipe failed while the wheel was halfway through rotation. Under load, the operator moved forward with a wheel at 45degrees. This bent the shaft.

We bought a replacement shaft from Combilift agents and it was fitted.

Upon commissioning the machine, we noticed that the RHS front wheel has a "toe-in" position. When switching the direction control lever from Sideways to Forward, the wheel is rotated to face 100% forward (as expected), but after about 10 seconds it starts to "creep" to a "toe-in" position again.
Measuring on the RHS (primary) shaft, this equates to about 9mm of "creep".

I suspect the air is entrapped in the hose between the two cylinders.
Some advice from technicians was to repeatedly switch the direction control lever from Carousel mode to Straight mode so as to "work out" the air.

I'm sceptical about the "self bleeding" capabilities of the Secondary (LHS) and hose connection the LHS and RHS cylinder: my reasoning is that the volume of hydraulic fluid in the cylinder + hose (called the "Synchronised Oil") is more than that of the volume of fluid moved in on stroke (cylinder volume). Hence, how can the system ever get rid of air in the Synchronised Oil line?

I guess the question then boils down to: What is the proper bleeding procedure when installing a new steering cylinder?

Any thoughts?

Thank you!