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

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the end of the short lever 274276-4 proj ects
out of the block and remove the nut 206513-6
and the screw 274252-5.
(b) To remove the stroke control piston. - (Refer
dr. no. 274280-1.) Remove the five mounting
screws 196780-4 from the stroke control piston
retainer 274278-1. The piston and retainer
can now be pulled out of the valve block.
Care must be taken not to injure the oil seal
leather 274273-8. When reassembling these
parts, first assemble the piston in to the
block, and then assemble the retainer.
(c) To remove the "S" valve (servo). - (Refer dr.
no. 274283-1.) First remove the control pump
by-pass valve and the servo valve can be withdrawn
from the block. The servo valve can be
removed from the valve block, without removing
the block from the A-end. This is accomplished
by draining the A-end and removing the
A-end inspection covers 274298-2. Reach up
through the inspection openings, and remove
the nut 206513-6 and the screw 274273-10, which
secures the servo valve 274283-1 to the servo
control link 274275-3. Nowremove the control
pump by-pass valve. Next remove the servo
valve end cover 274280-5, and the servo valve
can be pushed out of the valve b~ock. When a
new valve is to be assembled, the valve will
have to be ground to agree with drawing number
274283-1. The outside diameter of the
valve will be 0~010 oversize and will have to
be ground to fit the valve block to give a
clearance of O'.'OOJ5to0'JO007 inches. The 45°
chamfer, and the 1/8" side slots are to be
ground on the lands of the valve in accordance
with drawing number 274283-1. The lines of
seal on the valve are to be determined from
each individual valve block as follows:
(1) Assemble the valve in the valve block, with
the control pump by-pass valve in place.
The large end cover 274275-1 must be off.
With the valve installed and the cam on the
end of the by-pass valve turned so as to ~rmit
practically no movement of the valve J
the distance from the end of the valve to
the valve block cover face 274275-1 is to be
accura tely measured with a depth micrometer.