DISASSEMBLY PROCEDURE
Remove all gas lines and suction/discharge fittings from
pump. This is accomplished by using a flatbladed
screwdriver. Slide the retaining clips away from the gas
“in,” suction and discharge fittings. Then pull the fitting
away from pump body.
Using a 5/16” (8 mm) socket, remove the 4 nuts and
washers and pull out the body bolts.
The end caps, mounting brackets will separate from the
pump. Grab a piston in each hand and twist each side
counterclockwise. Remove the piston, diaphragm,
piston seal and retaining washer from one side of the
drive shaft.
Place drive shaft into a vise with wood block jaws and
rotate counterclockwise to release old diaphragm.
Install new diaphragm and hand tighten.
CAUTION: Do not damage the surface of the drive shaft.
Using a razor blade or sharp knife, cut label on the front
of the pump along the seam in center of body.
With pump label facing you, slowly pull body apart.
Disconnect exhaust hose from muffler and pull spool
valve stem from body. Discard body gasket and old
spool valve subassembly.
To assemble new spool valve subassembly, insert
internal exhaust hose spring into exhaust hose. Connect
hose to spool valve. Mount torsion springs into spool
valve straight side first. Push torsion springs through
spool valve to bent/hook end. Lubricate spool valve
stem and insert stem into left side of pump body making
sure torsion springs are positioned in retaining niches.
Carefully push spool valve into pump until torsion
springs snap inward and lock into place. Reconnect
exhaust hose to muffler fitting.
CAUTION: If exhaust hose is not reconnected to
muffler fitting, pump will not operate.
Position new body gasket and the two o-rings and press
pump body together. Reinsert gas “in’’ fitting, discharge
and suction fitting into pump and slide retainer clips over
fittings until they snap into place. This will help hold the
pump together during assembly.
Lubricate and carefully reinsert the drive shaft through
the pump body. Install new diaphragm and piston
assembly onto drive shaft and hand tighten. Note
positioning and direction each part is facing.
Position end caps onto pump body. Insert body bolts
through pump body. Install washer, split washer and hex
nut on each bolt.
Note: Remember to insert mounting bracket into niches
on the body before installing end caps and bolts.
With a 5/16” (8 mm) nut driver, alternately tighten each
body bolt maintaining even pressure around pump body.
Using a 5/16” (8 mm) torque wrench tighten body bolts
to 20 inch lbs.
1
1
2a
2b
4
3
4
5
5
5
5
2a
5
4x
2b
4x
Santoprene
Geolast
Viton
Buna
Santoprene
Geolast
Viton
Buna
Key
Part No.
Description
Qty
1
20467-005
Kit, Check Valve Assembly, Buna
4
20467-006
Kit, Check Valve Assembly, Viton
®
4
20467-007
Kit, Check Valve Assembly, Santo
®
4
20467-008
Kit, Check Valve Assembly, Geolast
4
2a
20466-005
Kit, Diaphragm (incl. Pistons), Buna
2
20466-006
Kit, Diaphragm (incl. Pistons), Viton
®
2
2b
20466-007
Kit, Diaphragm (incl. Pistons), Santo
®
2
20466-008
Kit, Diaphragm (incl. Pistons), Geolast
2
Key
Part No.
Description
Qty
3
20469-005
Kit, Spool Valve & Springs, Buna
1
20469-006
Kit, Spool Valve & Springs, Viton
®
1
20469-007
Kit, Spool Valve & Springs, EPDM
1
20469-008
Kit, Spool Valve & Springs, Geolast
1
4
20468-005
Kit, End Caps
2
5
20465-001
Kit, Hardware
1
MODEL N5100 SERIES EXPLODED VIEW
**For optional port fittings, see F100-112**
