Displacement Pump Service
Disassembly
When disassembling the pump, lay out all removed
parts in sequence, to ease reassembly.
Clean all the parts thoroughly when disassembling.
Check them carefully for damage or wear, replacing
parts as needed.
1. Remove the displacement pump from the air
motor
as explained.
2. Unscrew the intake valve housing (19) from the
pump housing (9). If it is difficult to remove, squirt
penetrating oil around the threads and
gently
tap
around the valve housing with a plastic hammer
to
loosen it.
3. Remove the ball stop pin (15), o–ring(17),
retainer (16), and ball (18), ball guide(22), from
the intake housing (19).
4. Loosen the packing nut (24). Push the
displacement
rod (12) down as far as possible, then pull it out
the bottom of the pump housing (9).
5. Secure the flats of the displacement rod (12) in a
vise. Screw the piston stud(14) out of the rod .
Remove the ball(13), reatainer(21), packings(5,6)
And glands(4,7).
6. Remove the packing nut (24), throat packings
(5.6)
and glands (4,7) from the pump housing (9).
7. Inspect all parts for damage. Clean all parts and
threads with a compatible solvent before
assembling. Inspect the polished surfaces of the
displacement rod (12) and sleeve (11) for
scratches,
scoring or other damage, which can cause
premature packing wear and leaking. To check,
run a finger over the surface or hold the part up
to the
light at an angle. Be sure the ball seats of the
piston and intake housing are not chipped or
nicked. Replace any worn or damaged parts.
NOTE:
If the sleeve (11) needs replacement and is
hard to remove, contact your FLOTECH
distributor.
Reassembly
1.
Lubricate the throat packings and install them in
The outlet housing (9) one at a time as follows,
with the lips of the v–packings facing down:
the
male gland (4), one teflon (6), two leather(5),
one teflon (6), one leather (5), one teflon (6),
and the female gland (7). Install the packing nut
(24) loosely. See the throat packing detail.
2.
If you removed the sleeve (11), reinstall it in the
pump housing (9), making sure to replace the
gasket (10).
Be sure the tapered end of the
sleeve
faces down, toward the pump intake.
3. Lubricate the piston packings and install them
onto
the piston stud (14) one at a time in the
following
order,
with the lips of the v–packings facing up:
the
female gland (7), one Teflon (6), two leather (5),
one Teflon (6), one leather (5), one Teflon (6),
the male gland (4), and the packing retainer
(21). See the piston packing detail.
4. DO NOT use thread sealant on the piston
stud(14)
Install the piston ball (13) on the piston and
screw
the piston valve assembly into the displacement
rod (12). Torque to 65–75 ft–lb (88–102 N.m).
5. Insert the displacement rod (12) into the bottom
of
the pump housing (9), being careful not to
scratch
the sleeve (11). Push the rod straight up until it
protrudes from the packing nut (24).
6. Install the ball (18), o–ring (17), retainer(16),
and ball stop pin (15), ball guide(22), in the
intake valve housing (19). Apply thread
lubricant and Screw the intake housing into the
pump housing (9). Torque to 75–100 ft–lb
(102–136 N.m).
7. Reconnect the displacement pump to the air
motor as explained.