3-39. HIGH PRESSURE PUMP (R.O. PUMP) MAINTENANCE - continued.
Fluid Cylinder (10). Inspect block for cracks, gouges, stripped threads and other visible damage. Replace
cylinder if cracked or severely gouged, or if threads are stripped.
Valve Seats (7 and 34). Check valve seats for wear, scratches, stripped threads and other damage.
Replace seats if unserviceable.
Plungers (20). Check for cracks and chips in ceramic coating of plungers and damaged/stripped connecting
nut or nut retainer. Replace plunger if chipped, or cracked If connecting nuts and/or retaining rings are
damaged, replace them.
Miscellaneous hardware. Check all remaining hardware for cracks, damaged threads, excessive wear,
corrosion, deformation and other damage making the item unserviceable. Replace unserviceable items.
Repair of pump assembly at the fluid end is limited to replacement of defective components
Place valve block on a clean work bench and install valve seats (7 and 34) as follows.
(1) Lay valve seats on top of valve seat bores.
(2) Position socket from valve seat removal tool on top of seat and, using a drift pin and hammer tap lightly
until seats are firmly lodged in valve block.
Install disks (33), springs (31 and 32) valve guides (30) and screws (29) on valve seats (34). Torque screws
to 25 lbs ft.
Install disks (6), springs (5), valve guides (4) and screws (3) on valve seats (7). Torque screws to 25 lbs ft.
Position O-rings (2) on caps (1) and install caps (1) with O-rings, plate (9) and screws (8). Torque screws to
80 lbs ft in sequence as illustrated.
If removed, install studs (13), plugs (11 and 12), nuts (21) and retainers (22).
Position O-rings (28), stuffing boxes (27) and plate (14) on fluid cylinder (10) and secure with eight screws
(15). Torque screws to 40 lbs ft in sequence as illustrated.
Insert packing bushings (16), two Utex packings (17), and packing bushings (18) in stuffing boxes (27). Tap
lightly with a soft mallet to insure proper seating.
Insert plungers (20) in stuffing boxes (27) and install gland nuts (19) fingertight.