10
Pump Disassembly:
This operation must be performed
before continuing to the following sections. See page
11 for applicable repair kits.
Grip the upper pump body (25) in a padded-jaw or
smooth-jaw vise. Unscrew air piston tube (22), with
cap (17) attached, from the upper body. Unscrew the
pump tube (35), with footvalve (37) attached, from
the lower body (31).
Place a 1/4” diameter rod through hole at the bottom
of the lower pump rod (7). Use an adjustable wrench
to unscrew the fluid piston (15) from the pump rod.
Remove ball (14) and set aside. Grip air motor
assembly (1) by hand and pull out the entire assembly
(air motor and both pump rods). Wrap the pump rods
to prevent damaging the surfaces. Keep the lower
spring (23) with the rod.
Upper Body O-ring Replacement:
O-ring (24) can
be removed by using a curved pick or small-bladed
screw driver. Wipe O-ring groove to remove debris
and replace.
Lower Body Seal Replacement:
This seal must be
replaced each time the lower rod is pulled through
the body.
The wiper seal (30) is replaced by removing screws
(33) and washers (32) and separating the upper (25)
and lower (31 ) body sections. Use snap ring pliers
to remove the retaining ring (28). Remove the backup
ring (29) and seal (30). Apply Balcrank lubricating
grease (p/n 826733) to the seal area and install a
new seal flairedside down. Work carefully to avoid
seal tearing around the snap ring groove. Reassemble
in reverse order.
Lower Spring and Air Motor Replacement:
Replace
the spring (23) by sliding off the old spring and sliding
on the new part. The air motor (1 ) is a 1 -piece, staked
assembly that cannot be disassembled for repair of
internal O-rings or upper seal. Replace the entire
assembly using Balcrank Repair Kit 827711.
Wrap the upper pump rod (2) with protective sheet
material or use wood/plastic blocks to grip it in a vise.
Use a wrench to remove the air motor assembly at the
hex adaptor/pump rod (1/2) joint.
Note:
If the upper
pump rod needs replacement, do so before the new
air motor is installed (refer to Replacing the Upper
Pump Rod). Apply thread adhesive to the air motor
before installation.
Upper Spring and Flat Seal Replacement:
Unscrew cap (17) from air piston tube (22). Remove
screw (21), spring retainer (20) and spring (19) and
lift out upper gasket (Item 18, 1 of 2). Reassemble in
reverse order. Replace the lower gasket (Item 18,2
of 2) while the tube is off the body (25). Be sure the
new gasket is flat against the body before assembling
the tube.
Replacing Parts in the Footvalve:
Grip pump tube
(35) and footvalve (37) with separate pipe wrenches.
Unscrew the footvalve, drive out retainer pin (38) with
a 1/8” diameter punch, remove lower ball (14) and/or
O-ring (36) as necessary. When reassembling the
pump tube to the lower pump body, be sure to check
the upper O-ring (34) for damage and replace as
necessary. Apply grease to the footvalve threads and
O-rings (34,36) and reassemble.
Replacing the Upper Pump Rod:
Grip only the upper
rod in a vise. Use a 1/8” spanner wrench to remove
the floating joint adapter (5) and air motor assembly
( 1 ) from the upper rod. Wrap the replacement upper
rod in protective material before placing in the vise.
Apply thread adhesive to both internal threads of the
pump rod and reassemble the connecting parts.
Replacing the Lower Pump Rod:
Grip only the
lower rod in a vise. Use a 1/8” spanner wrench to
remove the floating joint adapter (5) from the upper
rod (2). Wrap the upper rod and air motor assembly
and set aside.
Use an adjustable wrench to remove lock nut (3). Slide
offwasher (4) and adapter (5). Remove connecting
rod (6) with a pipe wrench. Wrap replacement lower
rod in protective sheet material before placing in the
vise. Apply thread adhesive to the connecting rod
and reassemble with the short thread length into the
rod. Replace the washer, adapter and nut. Tighten
nut completely then back off 1/4-tum to allow free
movement of adapter. Apply thread adhesive to the
adapter and reassembly.
Pump Reassembly:
Apply grease to the lower pump
rod end, wiper seal (30) and O-ring (24). Slide the
lower spring (23) over the upper pump rod and then the
entire upper rod/lower rod/air motor assembly through
the pump. Some resistance will be encountered as the
lower rod passes through the wiper seal. Reinstall the
upper ball (14) and piston (15). Insert a 1/4” diameter
rod through the pump rod and tighten the fluid piston
with a wrench. File off any burrs or raised areas created
during the repair process.
Grease O-rings (16,34) and pump tube (35) threads
before reassembling to the body. Tighten with a pipe
wrench. Grease the air motor assembly and inside
the tube (22), reassemble and tighten with a strap
wrench.
PUMP SERVICING
