Schaerer 7300 - Seat Cylinder Pilot Operated Check Valve Removal; Installation

SECTION IV
MAINTENANCE / SERVICE
4.18 Seat Cylinder Pilot Operated Check
Valve Removal / Installation
A. Removal
(1) Remove seat cylinder (Perform steps 1 thru 16
of para 4.16).
(2) If removing pilot operated check valve which
affects input to rod end of seat cylinder, perform
the following steps before proceeding to step 4:
a. Remove large plug (1, Figure 4-28) from
lower manifold (2).
b. Remove fitting connector (3) and fitting seal
(4) which connects tube (5) to upper mani-
fold (6).
c. Disconnect tube (5) from male connector (7).
d. Remove male connector (7) from lower
manifold (2).
(3) If removing pilot operated check valve which
affects input to base of seat cylinder, perform
the following steps before proceeding to step 4:
a. Remove small plug (A, Figure 4-28) from
lower manifold (2).
b. For R.H. seat cylinder, remove large plug (B)
from lower manifold (2). For L.H. seat
cylinder, disconnect hose (C) from male
connector (D); then remove male connector
(D) and reduction fitting (E) from lower
manifold (2).
(4) Using a long, thin needle nosed pliers, unscrew
guide shaft (8) and remove spring (9), washer
(10), nylon washer (11), and check valve (12)
from lower manifold (2).
(5) Using a small punch or Allen wrench, push pilot
piston (13) out of lower manifold (2).
(6) Remove spring (14) from lower manifold (2).
B. Installation
(1) Clean all metal components with degreasing
solution and allow to air dry. Flush out lower
manifold (2, Figure 4-28) using clean oil.
(2) Install nylon washer (11) and washer (10) on
check valve (12).
(3) Install assembled check valve (12) and spring
(9) in lower manifold (2) and secure with guide
shaft (8).
CAUTION
Make sure guide shaft bottoms out. Fail-
ure to do so will result in improper func-
tioning of check valve. However, do not use exces-
sive force on guide shaft to prevent damaging
components.
(4) Using a long, thin needle nosed pliers, screw
guide shaft (8) inward until it bottoms out in
lower manifold (2); then unscrew guide shaft two
full turns.
(5) Install spring (14) and pilot piston (13) in lower
manifold (2).
CA7662
4
5
8
9
10
11
12
13
14
2
A
ROD END
INPUT PILOT
OPERATED
CHECK VALVE
BASE INPUT
PILOT OPERATED
CHECK VALVE
ADDITIONAL
COMPONENTS ON
L.H. CYLINDER
1
E
D
C
B
8
9
10
11
12
6
7
13
14
3
Figure 4-28. Seat Cylinder Pilot Operated
Check Valve Removal / Installation
Page 4-27Printed in U.S.A.
© Schaerer Mayfield USA, Inc. 2004