OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER

224
(C) Hydraulic chatter or hammer is caused by vibration
of a spring actuated valve, long pipes
not being secured by clamps, air in the system,
or excessive resiliency or binding in the
driven equipment.
(d) Squeals or hydraulic hum are caused either by
the head on auxiliary pump being clamped too
tight against the rotor, or by high frequency
vibration in the auxiliary or main pump relief
valves. Relief valve noises of this nature,
however, do not indicate mechanical or other
defects and for all practical purposes may be
disregarded.
47. Leakage either inside or outside of the system may
be the result of any of the following causes:
(a) Improperly fitted or torn gaskets.
( b ) Distorted or scored sealing rings or oil seals.
A single cut or scratch on the working surface
of these parts may cause a steady slow leak.
(e) Worn or scored valves.
(d) Worn or scored pistons in main pumpor hydraulic
motor.
(e) Scored valve plates in main pump or hydraulic
motor.
(f) Scored bushings in auxiliary pump.
Disassembly and Assembly
48. The remaining paragraphs of this chapter give instructions
as to disassembly of the elements of the hydraulic
equipment. In general, the equipment may be reassembled by
simply reversing the dismantling procedure. To aid in the reassembly
of the unit, it is desirable to mark all mating parts
such as cams, gears, linkages and adjustable pieces, so that
they may be replaced in the same relative position to each
other. This procedure will eliminate much unnecessary labor
in fitting tne parts, and also in final adjustment of the
equipment.
49. Disassembly of the A-end. - The components of the
; A-end unit and their reference drawings are:-