New Holland T8010 Manual page 740

HOW TO READ SYMBOLS IN A HYDRAULIC SCHEMATIC
Introduction
Accurate diagrams of hydraulic circuits are essential to the
man who must repair them. The diagram shows how the
components will interact. It shows the field technician how it
works, what each component should be doing and where the
oil should be going so that he can diagnose and repair the
system.
The purpose of this section is to show you how to find your
way around schematic circuit diagrams.
Circuit Diagrams
There are two types of circuit diagrams.
1. Cutaway Circuit Diagrams show the internal construction
of the components as well as the flow paths. By using
colors, shades or various patter ns in the lines and
pa s sa g es, t hey a r e abl e t o s how m any d if fe r e nt
conditions of flow and pressure. Cutaway diagrams take
cons iderably longer t o produc e beca use of their
complexity.
2. Schematic Circuit Diagrams the "shorthand" system of
the industry, are usually preferred for troubleshooting. A
schematic diagram is made up of simple geometric
symbols for the components and their controls and
connections.
Symbol Systems
There are several systems of symbols used when making
schematic diagrams. They are as follows:
I. S. O. = International Standards Organization
A. N. S. I. = American National Standards Institute
A. S. A. = American Standards Association
J. I. C. = Joint Industry Conference
A combination of these symbols are shown in this section.
There are differences between the symbols but there is
enough similarity so that if you understand the symbols in this
section you will be able to interpret other symbols as well.
Section 35 - Hydraulic Systems, 3PT - Chapter 1
35-1-3
Using Schematic Symbols
Reservoirs
VENTED RESERVOIR
710L8B
A rectangle with the top removed represents a vented
reservoir. A rectangle with the top in place represents a
pressurized reservoir.
PRESSURIZED RESERVOIR
710L8C
There are other schematic diagrams that show a slightly
different version of a pressurized reservoir, but the symbols
are similar and easily recognized. An oval with a short line on
top or a rectangle with curved sides represents a reservoir
that is pressurized.
RETURN LINE ABOVE
THE OIL LEVEL
Lines connected to the reservoir usually are drawn from the
top, regardless of where the actual connection is.
SUCTION LINE OR RETURN LINE
BELOW THE OIL LEVEL
If the hydraulic line terminates below the fluid level, it is drawn
all the way to the bottom of the symbol.
PRESSURIZED RESERVOIR
710L8D
PRESSURIZED RESERVOIR
710L8A
710L8E
710L8F