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

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can be withdrawn from the body. The pin 274341-6 is to be
driven out which will permit removal of the detent plunger
274257-3, and the spring 180233-6.
122. To reassemble the control pump by-pass valve. - Refer
dr. no. 274256. The parts are to be thoroughly cleaned
and reassembled by reversing the dismantling procedure. The
assembled valve is to be checked to permit free movement of
the valve, and then the tubing and linkage is to be replaced.
123. To remove the valve block assembly (dr , no. 274272).
The A-end tank is to be drained. The air vent and breather,
the control pump gear housing, with the control pump attached,
the filter assembly, and both solenoids are to be removed as
explained above. All tubing and linkage are to be disconnected
from the valve block flanges and levers. Next r-emove the
large pipe plug 274341-11 from the A-end pump housing 274292-1.
Reach into the opening at the top of the pump housing and remove
the slotted nut 274339-2. (See 274272 assembly drawing
of the valve block.) The pin 274.273-11 cart be kept from turning
by inserting a large screw driver through the pipe tapped
hole in the pump housing. The pin 274273-11 can be removed
through the same opening. T~e valve block assembly is a very
heavy unit, and a block and tackle or a chain fall must be
used for ease in handling the unit, when it is being removed
from the A-end. The verrt Lng valve control lever shaft 274281-5
assembly is to be removed by Loo serri.ng the four screws 196825-6.
Next remove the· two solenoid operating levers 274273-3 and
274273 by removing their clamp bolts 196780-4. Next remove
the fourteen solenoid housing mounting screws 196780-4, and
the housing can be lifted off. With the chain fall or block
and tackle secured to the eye bolts in the valve block assembly,
loosen the nineteen valve block mounting screws 206590-7. Insert
jack screws in the two 1/2 inch tapped holes in the pump
housing 274292-1. Turn the jack screws evenly and the valve
block can be slipped off the dowel pins 271727-11.
124. To dismantle the valve block assembly (dr . no.
274272). - In order to remove the internal parts from the valve
block assembly, the valve block must be removed from the A-end
as explained above. For ease in assembling and dismantling,
it is advisable to remove the block to a work bench. The parts
are to be removed as follows:
(a) To remove the valve block servo i i nkoge .« First
loosen the slotted nut 274339-2, and remove
the screw 274273-6 from the stroke control
piston 274280-1. Next loosen the slotted nut
206513-6, and remove the screw 274273-10 from
the "SI!valve (servo valve) 274283-1. Nowturn
the control lever 274272 -lor 274336-1, so that