What I would look for next is what happens when you give the steering wheel a slight "crowd" in either direction with wheels fully engaged with the ground.
What I would expect is pump pressure would rise as the spool moves and forces the boost/assist cylinder to move, then as the spool re-centers, the pump pressure would then drop back to zero (open-center/spool-neutral condition).
Another mental abstraction to think about (or from the viewpoint of) is that the system doesn't exactly "demand" pressure in my thinking. In retrospect, it "creates" backpressure (what the pump-output gauge is reading) by virtue of creating an effective restriction to fluid flow or presenting the ever-adding positive-displacement volume of fluid against a mechanical load (as in the case of a hydraulic cylinder).
Just a practical example of above, with a functioning system I would fully expect pump backpressure to be significantly lower when turning the tires on a film of slick mud vs. when they are half-buried up to the axles. In other words, even though the pump can produce 1400psi when thoroughly dead-headed, the pressure is "matched" to the mechanical "resistance" load applied in the opposite direction.
This post was edited by mattofvinings at 16:41:34 06/20/09 3 times.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Box Plow Blues - by Tom Schwarz. One of the first implements most tractor owners obtain is the box plow. For very little money, this piece of equipment promises to plow and flatten any hill or vale on your ranch road or farm. At least that's what I thought! As simple as a box plow appears, it can be rather challenging to make work correctly. In our sandy soils of Florida, traction is king. You can never have wide enough tires or heavy enough weights to get all the traction you want … unless you own a monster tractor. U
... [Read Article]
Latest Ad:
Oliver 550 Diesel runs like a watch three point hitch pto engine gone threw about two hundred hours ago nice clean tractor
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
