User's Manual

42000Modu-Flo
®
System
R
3-13
3.5 HYDRAULIC PUMP MAINTENANCE
(OPTION H2)
3.5.1 General. Maintenance tips, disassembly and
assembly procedures for hydraulic pump Option H2 are
discussed in Paragraphs 3.5.2 through 3.5.4. An exploded
view of the pump is shown Figure 3-4 and should be
referred to during the discussion.
3.5.2 Hydraulic Pump Option H2 Maintenance Tips.
3.5.2.1 The only maintenance required on the hydraulic
pump Option H2 is to check for the following:
a. Check four socket-head screws (11, Figure 3-4) to
make sure they are tight. Loose screws could allow air
and/or lubricant to leak between the pump and the
manifold. This condition could result in erratic pump
output.
b. Check for leakage past gasket (15). Replace gasket if
required.
c. Check jam nut (21) to make sure it is tight against
adjustment screw body (19). If the jam nut is loose, the
adjustment screw (13) could rotate and cause the
pump output to change. This condition could also
result in lubricant leakage or in air being sucked into
the lubricant.
3.5.2.2 If internal components of the pump are defective it
will usually result in erratic pump operation or output.
Section 9 of the manual lists causes and solutions for
problems which could occur in the Modu-Flo system. Before
disassembling any pump, refer to Section 9. The problem
may be caused by other conditions which can be checked
first before breaking down the pump.
3.5.3 Disassembly of Hydraulic Pump Option H2. The
procedure below describes complete disassembly of a
pump. However, you only need to disassemble to your
specific area of concern.
3.5.3.1 The disassembly procedure for the hydraulic pump
Option H2 is as follows:
sembled. If adjustment screw (13) requires removal,
perform the following:
(1) Remove adjustment screw cap (22) from adjust-
ment screw (13). Butt the adjustment screw cap
(21) against jam nut (22) and use the stamped
numbers on the cap to measure how far the
adjustment screw (13) extends from the jam nut.
Record this dimension.
(2) Remove jam nut (21) and two gaskets (20).
Discard gaskets.
(3) Remove adjustment screw (13) by screwing it
towards the hex portion of the adjustment screw
body (19) until it is free.
d. Remove cylinder cap (6). Remove and discard o-ring
(5).
e. Use wooden dowel or soft rod to push hydraulic piston
(2) and lube piston (1) from hydraulic cylinder (7).
Remove and discard o-rings (4 and 9) and backup
rings (24).
f. Separate hydraulic piston (2) from lube piston (1) by
removing groove pin (3).
3.5.4 Assembly of Hydraulic Pump Option H2.
NOTE
Use new o-rings and gaskets when assem-
bling pump. Lubricate all o-rings and sliding
parts with the lubricant which is used in the
system.
3.5.4.1 Assemble the hydraulic pump Option H2 according
to the following procedure:
a. Insert lube piston (1) into hydraulic piston (2). Insert
groove pin (3) to secure the assembly.
b. Install new o-ring (4) and backup rings (24) on hydraulic
piston (2). Install new o-ring (9) on lube piston (1). Push
piston assembly through hydraulic cylinder (7) into body
(10).
c. Install new o-ring (5) on cylinder cap (6). Screw cylinder
cap into hydraulic cylinder (7) and tighten securely.
d. Insert smaller end of adjustment screw (13) into
adjustment screw body (19). Rotate adjustment screw
(13) until smaller end is protruding from hex portion of
adjustment screw body (19).
e. Install new o-ring (12) on adjustment screw body (19)
and install adjustment screw body in body (10). Tighten
securely.
f. Install jam nut (21) and two new gaskets (20), one on
each side of jam nut, on adjustment screw (13). Butt
adjustment screw cap (22) against jam nut (21) and
turn adjustment screw (13) until the length it extends
beyond the jam nut is the same as the length recorded
during disassembly.
g. Install adjustment screw cap (22) on adjustment screw
(13).
h. Install new o-ring (26) on check seat (25) and install
check seat assembly into pump body. Install new ball
(29) and new check valve spring (16) into body (10).
NOTE
Figure 3-4 shows hydraulic cylinder (7) sepa-
rated from body (10). To achieve disassembly
to this level requires special tools to remove
hydraulic cylinder retainer (23). Normally, this
level of disassembly is only performed at the
factory. If scoring or wear marks are evident on
the inner diameter of hydraulic cylinder (7) or
body (10), the pump cannot be serviced and
should be replaced.
a. Separate pump from manifold by removing four socket-
head screws (11). Remove and discard three o-rings
(9) and one o-ring (18).
b. Remove enclosure screw (14). Remove and discard
gasket (15), check valve spring (16), steel ball (29),
check seat (25), and o-ring (26).
c. Remove adjustment screw body (19) and o-ring (12)
from body (10). Discard o-ring (12). Removal of
adjustment screw (13) from adjustment screw body
(19) will change output setting when pump is reas-