(12) Preparation For Dismantling Valve Bank - When it is necessary to detach and dismantle any of the valves
which make up the Valve Bank Assembly (Figure 12) it is necessary that the bank be disconnected from hydraulic hoses,
unbolted from the mounting brackets and moved to a totally clean work bench area free of wind borne particles and
surface dirt. The detached unit should also be plugged and washed clean externally before any dismantling is started.
Always support screed before uncoupling.
METHOD:
A - Remove electric coils according to Paragraph (10). If no coil exchange is to be made mark each coil and each
valve tube assembly from which it is taken so that a correct return will be assured. Remove the coils and lay them in a
safe area leaving the hot wires connected. If a coil change is to be made mark the hot wire number on the valve tube to
assure correct connection of the new coil.
B - Mark each hose and it's companion fitting on the valve bank with a code that will assure correct re-coupling
when the bank is installed. It is possible to accidentally connect hoses improperly if they are not marked. (Should
marking be forgotten or erased, refer to system diagrams Figures 1 and 2 for correct connection details.)
C - Disconnect hoses properly as described in Paragraph (22). As each hose is loosened plug the exposed end
with a clean plastic plug or wrap with a clean cloth cover and fasten securely. Do the same to the open fitting on the
valve bank. Do not leave any open hydraulic connector unprotected against wind borne particles.
D - Unbolt and remove the valve bank. Important! Scrub and rinse the exposed surfaces of the entire valve bank
to remove all dirt particles before the assembly is placed on a clean working surface and dismantled.
(13) Dismantling Valve Bank - The dismantling job must be performed in a clean area with tools that are free of
loose dirt particles. As the internal valve parts are removed they should be placed on a lint and particle free surface.
METHOD. (See Figure 12)
A - If a Throttle Valve (20) is to be inspected or cleaned unscrew it from the Holding Valve (19). Be sure to retain
O Ring (22).
B - If Holding Valve (19) is to be inspected or cleaned remove Cap Screws (24) and Lockwashers (28).
C - Remove Tie Bolt (25) and separate the valves. Be sure to retain all O Rings (23) which seal the bodies against
leakage.
D - See individual valve dismantling details, Paragraphs (14), (15), (16), and (17).
IMPORTANT - When assembling valve bank, tighten screws alternately,
evenly, and with not more than 150 inch pounds of torque. It is
important that the machined contact surfaces and O rings make a leak-
free contact without excessive screw tightness which can warp bodies
and cause binding of the spool.
(14) Dismantling Solenoid Valve (See Figure 10).
A - Unscrew and remove Hex Nut (1).
B - Remove Sleeve (2).
C - Carefully pull Coil (3) off tube Assembly (6). Never use a pry tool against the plastic wire protector.
D - Place housing (14) in a vise exerting only slight jaw pressure on the rough sides of the body casting to keep it
from turning when tube is unscrewed. Have the tube assemblies (6) horizontal so that loose parts will not fall out.
E - Using the special spanner wrench (15) provided in the paver tool box carefully unscrew the tube (6) from the
body (14). Note: It may be necessary to remove the paint and some metal from the spanner wrench pins to make them
fit the tube holes.
F - When the tube is removed, the loose parts; plug (9), pin (10), and plunger (8), can be emptied from the tube
interior.
G - Push pin (5) out of tube.
H - Remove spring (11) from housing.
I - If spool (13) is to be removed, both coil and tube assemblies should be removed first. Then pull out the retainer
(12) from each end of the spool and work spool (13) carefully out of housing (14). Important! The matched spool and
housing are precision parts which fit together with very little clearance. When removing or installing spool, gently work it
in or out with the fingers by small increments being careful not to bind it. Never use force other than a gentle tap with the
plunger (8).
Clean all parts except electric coils in a good solvent being certain to flush all particles out of the housing, spool,
tube, etc. Re-lubricate parts with clean hydraulic fluid. Re-use O Ring seals only if they are in near new condition,
otherwise a steady loss of hydraulic fluid will occur. Spool (inside the body) should be free of binding when moved
laterally. Free movement should not be affected by a 360 rotation of the spool while it is being moved laterally. If spool
movement is not free a replacement valve is recommended.
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