4. Insert a screwdriver in the piston shaft of the pump and
pull the piston out. Install the shaft on the handle at either
piston hole by placing a short clevis pin through the handle
and the piston shaft end and securing with the hitch clip pin.
NOTE: Select the upper piston hole on the handle for the 1/2-
gallon setting (Figure 3) or the lower piston hole for the
1/4-gallon setting. Flow settings can be changed at any
time by repositioning the piston shaft on the handle.
To Dispense Fluid
1. Remove the nozzle from its holder and insert into the
receiving tank of the equipment or vehicle.
2. Choose a handle setting for the desired flow rate:
– 1/4-gal. setting for low-volume, low-resistance pumping
– 1/2-gal. setting for high-volume, high-resistance pumping
3. To operate pump, manually move the handle in a push/
pull motion.
4. After dispensing the desired amount of fluid, drain the
hose and nozzle. Place the nozzle in its holder and return
the handle to its upright storage position.
During daily use, the GPI HP-100 Hand Pump is essentially
maintenance free. However, the pump should be inspected
periodically for signs of leakage. If leaks are present, make
appropriate repairs. Refer to the Troubleshooting section.
Figure 2
Figure 3
Figure 4
OPERATION & MAINTENANCE
NOTE: Lock the handle to the pump by pushing the handle
against the pump and inserting a padlock through either
of the top holes in the handle and through the pump’s lock
hole. (Figure 4)
SYMPTOM
PROBABLE CAUSE
CORRECTIVE ACTION
A. FLUID LEAKS AROUND
1. Packing seals settled
Tighten two screws on the retainer and torque to approximately 20 lb. in. (or hand
SHAFT SEAL
tighten then another half turn until leak stops)
2. Seals worn
Remove the two screws on the retainer and remove the retainer and bearing. Remove
all three seals and replace.
B. FLUID LEAKS AT
1. Anti-siphon valve or
Replace vent plug assembly. Remove the black cap. Remove old vent plug assembly
ANTI-SIPHON VALVE
O-ring damaged
by turning counterclockwise. Install new vent plug assembly. Replace cap.
C. LOW FLOW RATE
1. Inlet screen clogged
Remove the pump from the tank. Remove the suction pipe, spacer, and inlet
screen from the bottom of the pump. Clean the inlet screen and assemble. Place
the pump on the tank using installation instructions.
2. Suction pipe leak
Remove the pump from the tank. Inspect the spacer and suction pipe to ensure
they are not worn or damaged. Replace as necessary and install the suction pipe
and pump again using installation instructions.
3. Piston ring or liner
Remove the piston cover and inspect the piston ring and liner. Scoring and
worn
severe scuffing on the liner indicates wear. If necessary, install an Overhaul Kit.
4. Piston cracked
Remove the piston cover and inspect the piston. Install an Overhaul Kit, if necessary.
D. PUMP SEIZED
1. Debris in piston or
Disassemble and clean the piston and liner. Check for debris lodged in the
liner
piston ring or behind the liner. Small dimples in the liner indicate dirt, debris or
welding slag contaminants in the tank. Replace the piston ring and liner. If
appropriate, flush the tank of all contaminants.
TROUBLESHOOTING
Attach links to first hole
Use for 1/2 gallon setting
Use for 1/4 gallon setting
➤ ➤
➤➤ ➤➤
1/2 gallon setting
shown here
➤ ➤
3. Attach the free ends of the links to the bottom, outer
surfaces of the handle. Insert a long clevis pin through the
holes on both links and the lowest hole on the handle.
Secure with a small cotter pin. (Figure 2)
