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

314
vibration for equipments of this type. However
vhen operating using !!Manual1'control,
the noise and vibration in the equipment will
increase. This will be caused by the failure
of the control pump circuit which no longer
supercharges the main circuit lines. The noise
is caused by cavi ta tion in the oil, but no harm
will occur in the equipment if it is operated
slowly as explained in paragraph 65.
v (b) Popping and sputtering ar-e caus ed by air entering
the control pump through the intake
lines, and may be caused by leaking gaskets in
the suction line of the pump or damaged oil
seal on the control pump drive shaft.
(c) Grinding noisesare usually caused by dry bearings,
or gears, or foreign matter in the oil .
.(d) Hydraulic chatter or hammer is caused by the
vibration of a spring actuated valve,. long
pipes not securely fastened with clamps, or
air in the system.
(e) Squeals are caused by the head on the control
pump being clamped too tightly against the
pump rotor.
102. Leakage either inside or outside of the system may
be the result of any of the following causes:
(a) Threaded fittingS improperly tightened.
ning the threads of fittings or pipe plugs
usually aid in preventing leakage, when
are correctly tightened.
(b) Crossed threads in fittings.
(0) Improper fitted or torn gaskets.
Tinwill
they
(d) Distorted, scored or worn oil seals, sealing
rings, or packing. A single scratch or cut
on the working surfaces may cause a slow steady
leak.
(e) Flanged joints not seating squarely.
(r) Worn or scored valves.
(g) Worn or scored pistons in the motor or pump.