Instruction Sheet
P/N 229761-03
Iso-Flor HD Pump Repair Kit
Introduction
Use this instruction sheet to repair the Iso-Flo HD pumps used in the Iso-Flo
HD Automatic and Manual Voltage Block Systems with the Pump Repair Kit.
Materials Required
Have the following ready:
S Pump repair kit
S O-ring lubricant (Parker O-Lube or equivalent)
S PTFE tape
The repair kit includes square air and fluid cylinder O-rings, air piston, piston
nut O-ring, and fluid piston seal. Order separately any other parts required.
Refer to your Iso-Flo HD Voltage Block System manual for complete parts
lists.
Tools needed:
S
S
S
S
S
Side cutters
Small, thin-blade, flat screwdriver
12- and 15-inch or larger adjustable wrenches
Vise
1/4-inch hex wrench
Pump Removal
1. Flush the system with a compatible cleaning solution and expel as much
cleaning solution from the pumps as possible by toggling the RESET
valve.
2. See Figure 1. Number all air tubing (D) and fluid hoses (C) and their
corresponding fittings. Disconnect the tubing and hoses.
3. Remove the two screws and sealing washers (B) from the bottom of the
pump support bulkhead.
4. Remove the pump (A) from the Iso-Flo cabinet.
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Part 229761-03
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Iso-Flo HD Pump Repair Kit
Pump Removal
(contd)
D
D
A
A
DO NOT FILL CUP
ADD ONLY 1/2 oz.
TYPE “Q” SOLVENT
WEEKLY
D
DO NOT FILL CUP
ADD ONLY 1/2 oz.
TYPE “Q” SOLVENT
WEEKLY
C
C
B
C
Automatic HD Pump
B
Manual HD Pump
Figure 1 Pump Removal and Installation
A. Pump
B. Screws and sealing washers
C. Fluid hoses
D. Air tubing
Pump Disassembly
See Figure 2.
1. Use a 1/4-inch hex wrench to remove the air cylinder screws (A) from
the top of the air motor head (B).
2. Remove the air motor head.
3. Pull up on the air motor cylinder (C), tilting and twisting it to pull it off the
air piston (2).
NOTE: If you are only replacing the air motor piston, you do not need to
perform the rest of the steps in this procedure.
4. Use the hex wrench to remove the fluid cylinder screws (F).
5. Remove the center head (G) and piston and shaft assembly.
6. Pull the fluid cylinder (H) off the fluid piston (I) and base head (J).
Part 229761-03
E 2015 Nordson Corporation
Iso-Flo HD Pump Repair Kit
3
B
1
C
F
A
Top View
D
3
2
Apply O-ring lubricant to all O-rings
before installing.
L
Apply O-ring lubricant to inside wall and
top and bottom lips before installing.
E
Apply O-ring lubricant to piston seal
and bottom of piston before installing.
1
O-ring lubricant: Nordson part 900223
(Parker O-Lube or equivalent)
1
or
1A
G
H
K
I
4
J
1
or
1A
Figure 2 Pump Cutaway (1:1 Automatic Pump Shown)
1.
1A.
2.
3.
4.
A.
B.
Square O-rings*
Square O-rings (2:1 pump)**
Air piston*
Piston nut O-ring*
Fluid piston seal*
Air cylinder screws
Air motor head
C.
D.
E.
F.
G.
Air cylinder
Upper jam nut
Lower jam nut
Fluid cylinder screws
Center head
H.
I.
J.
K.
L.
Fluid cylinder
Fluid piston
Base head
Shaft
Spacer (automatic pump
only)
Note: *−Pump repair kit parts.
Note: **−All parts called out are same for both automatic and manual pumps, except for the spacer (L), which is used
only on automatic pumps, and the 2:1 pumps, which have two sizes of square O-rings (1, 1A) because the fluid
cylinder has a smaller diameter than the air cylinder.
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Part 229761-03
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Iso-Flo HD Pump Repair Kit
Air Motor Piston Replacement
See Figure 2.
1. Hold the lower jam nut (E) with a 15-inch adjustable wrench. Remove
the upper jam nut (D) with a 12-inch adjustable wrench.
2. Remove the air piston (2) from the shaft (K).
3. Screw the lower jam nut down the shaft until it stops.
4. Remove the piston nut O-ring (3) from the lower jam nut. Lubricate the
new O-ring and install it in the jam nut groove.
5. Center the new air piston on top of the lower jam nut.
6. Thread the upper jam nut down the shaft until it stops. Place a wrench
on the shaft flats to prevent it from turning. Tighten the upper jam nut on
the shaft until snug.
7. Slide the air piston up until it fits into the boss on the upper jam nut.
8. Hold up the air piston and screw the lower jam nut upwards by hand
until it contacts the piston. Tighten the lower jam nut.
9. Make sure the inside wall of the air cylinder (C) is smooth and free of
nicks and burrs. If any are present, replace the cylinder.
Fluid Piston Seal Replacement
See Figure 2.
CAUTION: Do not scratch the fluid piston seal groove. Any scratches will
cause the pump to leak.
NOTE: The shaft (K) and fluid piston (I) are not serviceable. If they are
damaged, you must replace the pump.
1. Carefully slide a thin flat-bladed screwdriver under the fluid piston
seal (4).
2. Pry the seal out of the groove far enough to cut it with side cutters.
3. Clean the seal groove and make sure there are no scratches in the
groove surfaces.
4. Center the seal on the piston, making sure the seal lip faces the bottom
of the piston.
5. Push the seal over the piston with your palms until it fits into the groove.
Be careful not to damage the seal lip.
6. Clean the inside of the fluid cylinder with a compatible solvent such as
alcohol. Make sure the inside wall of the cylinder is smooth and free of
nicks and burrs. Replace the cylinder if it is damaged.
7. Apply a thin layer of O-ring lubricant to the inside wall of the fluid
cylinder.
Part 229761-03
E 2015 Nordson Corporation
Iso-Flo HD Pump Repair Kit
5
Pump Assembly
See Figure 2.
1. If you have not done so already, remove the square O-rings (1) from the
air motor head (B), center head (G), and base head (J). Apply O-ring
lubricant to new square O-rings and install them in the grooves in the
heads. Make sure the O-rings are not twisted in the grooves.
NOTE: One end of the fluid cylinder (H) has a chamfer on its inside
diameter. Install the fluid cylinder so that the chamfered end is against the
center head (G).
2. Install the fluid cylinder (H) into the O-ring groove on the base head,
then guide the fluid piston (I) into the cylinder. Make sure the top lip of
the cylinder fits into the O-ring groove in the bottom of the center head.
3. Install the four socket-head screws (F) through the center head as
follows:
CAUTION: Do not overtighten screws. Excessive torque will damage
cylinder. Use a hex wrench less than 100 mm (4 in.) long.
a. Use a crisscross pattern to install the screws (3) until the screw
heads contact the air motor head.
b. Using a crisscross pattern, tighten each screw to 3.4 NDm (30 in.-lb).
c. Using a crisscross pattern, tighten each screw to 6.8 NDm (60 in.-lb).
d. Using a crisscross pattern, tighten each screw to 9 NDm (80 in.-lb).
4. Install the air motor cylinder (C) by tilting it over the air motor piston (2).
Gradually tip the cylinder until it is vertical and the air piston is
completely inside the cylinder.
5. Push the air motor cylinder down and fit the lower cylinder lip into the
O-ring groove in the center head.
6. Install the air motor head on the air cylinder. Make sure the top lip of the
cylinder fits into the O-ring groove in the air motor head.
7. Install the four socket-head screws (A) through the air motor head and
tighten them using the procedure in step 3.
Pump Installation
See Figure 1.
1. Install the pump (A) on the pump support bulkhead and secure it with
the screws and sealing washers (B).
2. Connect the air tubing (D) and fluid hoses (C) to their corresponding
fittings.
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Part 229761-03
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Iso-Flo HD Pump Repair Kit
Kit Parts Lists
1:1 Manual and Automatic Pumps
See Figure 2.
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Item
—
1
2
3
4
Part
223723
940470
323717
940190
223195
Description
Kit, HD, pump repair (1:1 pump)
S O-ring, Buna-N, square, 4.500 x 4.625 in.
S Piston, air
S O-ring, hot paint, 0.813 x 0.938 x 0.063 in.
S Seal, Polypack, polymite with Viton
Quantity
1
4
1
1
1
Note
2:1 Manual and Automatic Pumps
See Figure 2.
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Item
—
1
1A
2
3
4
Part
1050910
940470
323061
323717
940190
231413
Description
Kit, HD, pump repair, Iso-Flo, 2:1
S O-ring, Buna-N, square, 4.500 x 4.625 in.
S O-ring, Buna-N, square, 3.25 x 0.068 in.
S Piston, air
S O-ring, hot paint, 0.813 x 0.938 x 0.063 in.
S Seal, Polypack, polymite with Viton,
3.25 in.
Quantity
1
2
2
1
1
1
Note
Issued 8/15
Original copyright date 1996. Iso-Flo, Nordson, and the Nordson logo are registered trademarks of Nordson Corporation.
Viton is a registered trademark of E.I. DuPont de Nemours and Company.
Part 229761-03
E 2015 Nordson Corporation