Hydraulics Routing. Why go to PTO first?

[The Highlander]

So. I've noticed that some tractors hydraulics route the following way:

Pump - PTO valve - Loader

Where as others do:

Pump - Loader valve - PTO (rest)

What is the advantage of one vs the other?

Thanks

 

[RickB]

Are you confusing PTO with three point hitch?

 

[The Highlander]

According to the parts catalog it goes into the PTO valve. Maybe the pto is actuated via hydraulics. This would provide a smoother engagement and also easier to control for the automatic functions for when you lift the 3pt hitch.

This also makes sense on why the test for deplorable diesel hydraulic pump flowed more when the PTO was applied vs not applied.

 

[RickB]

PTO control valves usually use regulated circuit pressure (low pressure), not full pump pressure like typical hydraulic functions. But I am not qualified to speak about TYM tractors.

 

[LouNY]

Most tractors that I have seen, used or worked on if factory loader equipped routed the main hydraulics from the pump
to the loader valve to any remote valves then to the 3 point.
When using hydraulic engaged PTO many use the power steering circuit which often also goes to the brakes.

 

[oldnslo]

If PTO is after loader valve the PTO would potentially disengage anytime a loader function was operating taking all the available flow.

Agree with LouNY that majority of tractors use steering circuit for PTO & brakes if hydraulic brakes