Repair
311391F
5
Piston and Cylinder Seals
Disassembly
1. Relieve pressure, page 3.
2. Turn OFF the main disconnect and lock out power at
the source.
3. Disconnect the pump inlet and outlet lines; see your
proportioner repair manual. Remove the four screws
holding the pump outlet flange (235) to the hydraulic
cylinder. Remove the linkage pin from the clevis
(221) to disconnect the pump from the drive. Take
the pump assembly to a workbench.
4. Remove the four nuts (209) and washers (206).
Unscrew the tie rods (234) from the flange retainer
(238). See the parts drawing on page 6.
5. Remove the flange retainer (238) and the cylinder
seals and gasket from the outlet flange (235). Note
that the A-side and B-side pumps are not the same.
See Details A and B in the parts drawing.
6. Pull the outlet flange (235) off the tie rods (234).
Remove the tie rods (234), cylinder (215), o-rings
(201), and piston assembly (239). The crossover
tube (233) will come loose.
7. If necessary, remove the retaining ring and piston
pin Unscrew the piston body from the piston shaft.
Remove the piston parts. See Parts drawing.
8. Thoroughly clean all parts in a compatible solvent
and inspect for wear or damage. Replace as
required.
Reassembly
1. Assemble the piston parts on the piston body, using
the new parts in the piston seal kit (218*). See Parts
drawing on page 6. Apply Loctite (supplied with kit)
to piston body threads. Screw the piston body into
the piston shaft and torque according to Table 1 on
page 6.
2. Install the cylinder seal kit parts (219†) into the out-
let flange (235), as shown in the Parts drawing. On
A-side pumps only, install the adapter flange ring
(241). Do not install the gasket (219c†) or flange
retainer (238) yet.
3. Slide the tie rods (234) through the outlet flange
(235). Install the gasket (219c†) and flange retainer
(238), oriented as shown. Screw the tie rods into the
flange retainer.
4. Lubricate the o-rings (201) and install them in the
grooves of the outlet flange (235) and pump base
(236). Lubricate the piston body and shaft, and slide
the piston assembly into the cylinder (215). Seat the
cylinder in the outlet flange (235), so the piston rod
slides through the cylinder seals (219†) and flange
retainer (238).
5. Check that the o-rings (202, 210) are in place on
each end of the crossover tube (233). Seat the
crossover tube in the outlet flange (235).
6. Orient the outlet flange (235) to the pump base
(236) as shown, guiding the tie rods (234) through
the pump base (236) to seat the cylinder (215) and
crossover tube (233) in the pump base.
7. Install the four nuts (209) and washers (206) on the
tie rods (234). Torque to 30 ft-lb (41 N•m).
8. Reconnect the pump to the hydraulic cylinder.
Reconnect the pump inlet and outlet lines.
Piston Seal (218*) and Cylinder Seal (219†) Repair
Kits are available. See Table 2 on page 8 to order
the correct kits for your pump. Also see kit manual
311356.
CAUTION
To prevent cross-contamination of the equipment’s
wetted parts,
never
interchange component A (isocy-
anate) and component B (resin) parts.
