New Holland Super Boom C185, Repair Manual

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DISTRIBUTION SYSTEMS ­ PRIMARY HYDRAULIC POWER SYSTEM
PRIMARY HYDRAULIC POWER SYSTEM ­ Cleaning
1. Contamination in the hydraulic system is a major
cause of the malfunction of hydraulic components.
Contamination is any foreign material in the hydraulic
oil. Contamination can enter the hydraulic system in
several ways.
(A) When you drain the oil or disconnect any line.
(B) When you disassemble a component.
(C) From normal wear of the hydraulic components.
(D) From damaged or worn seals.
(E) From a damaged component in the hydraulic sys­
tem.
2. All hydraulic systems operate with some contam­
ination.
The design of the components in this
hydraulic system permits efficient operation with a
small amount of contamination. An increase in this
amount of contamination can cause problems in the
hydraulic system. The following list includes some
of these problems.
(A) Cylinder rod seals leak.
(B) Control valve spools do not return to neutral.
(C) Movement of control valve spools is difficult.
(D) Hydraulic oil becomes too hot.
(E) Pump gears, housing, and other parts wear
rapidly.
(F) Relief valves or check valves held open by dirt.
(G) Quick failure of components that have been
repaired.
(H) Cycle times are slow; machine does not have
enough power.
3. If your machine has any of these problems, check
the hydraulic oil for contamination. See types of con­
tamination below. If you find contamination, use the
Portable Filter to clean the hydraulic system.
NOTE: There are two types of contamination, microscopic
and visible.
4. Microscopic contamination occurs when very fine
particles of foreign material are in suspension in the
hydraulic oil.
5. These particles are too small to see or feel. Micro­
scopic contamination can be found by identification
of the following problems or by testing in a laboratory.
Examples of the problems:
(A) Cylinder rod seal leak.
(B) Control valve spools do not return to NEUTRAL.
(C) The hydraulic system has a high operating tem­
perature.
87630288 1 6/6/2007
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