VERDER AIR VA 25 Operation manual

INSTRUCTIONS–PARTS LIST
Air-Operated
Diaphragm Pumps
819.0254
Rev. L
EN
Intended for use in accordance with the United States Flammable and Combustible Liquids
Code (NFPA 30) and the Automotive and Marine Service Station Code (NFPA 30A).
For professional use only.
VERDER VA 25
Evacuation and Transfer Pumps
120 psi; 0.84 MPa; 8.4 bar Maximum Fluid Working Pressure
120 psi; 0.84 MPa; 8.4 bar Maximum Air Input Pressure
Part No. 810.0780*
with TPE diaphragms and seats, acetal balls
Part No. 810.0930*
with TF diaphragms and balls, fluoroelastomer seats
Patent No.
CN ZL94102643.4
FR 9408894
JA 3517270
US 5,368,452 Important Safety Instructions
Read all warnings and instructions in this manual.
Save these instructions.
This symbol on the nameplate means the
product is listed by Underwriters
Laboratories Inc. (UL Standard No. 79,
Standard for Power-Operated Pumps for
Petroleum Product Dispensing Systems).
II 2 GD
Ex h IIC 66°C...135°C Gb
Ex h IIIC T135°C Db
*
Model 810.0780
ATEX T-code rating is dependent on the temperature of the fluid
being pumped. Fluid temperature is limited by the materials of the
pump interior wetted parts. See Technical Data for the maximum
fluid operating temperature for your specific pump model.

2 819.0254
Table of Contents
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Tightening Screws Before First Use . . . . . . . . . . . . . . .5
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Mountings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Air Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Waste Oil Receiver Evacuation System, or
General Fluid Transfer Application . . . . . . . . . . . .7
Gear Oil Evacuation System . . . . . . . . . . . . . . . . .7
Fuel Dispense System . . . . . . . . . . . . . . . . . . . . . .8
Pressure Relief Valve (Fuel Dispense Systems) . . . . .8
Changing the Orientation of the Fluid Inlet
and Outlet Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Air Exhaust Ventilation . . . . . . . . . . . . . . . . . . . . . . . . .9
Fluid Pressure Relief Kit
(for Pump Model 810.0780 only) . . . . . . . . . . . . . . .10
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Pressure Relief Procedure . . . . . . . . . . . . . . . . . . . . .11
Flush the Pump Before First Use . . . . . . . . . . . . . . . .11
Starting and Adjusting the Pump . . . . . . . . . . . . . . . .12
Pump Shutdown (All Systems) . . . . . . . . . . . . . . . . . .12
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Flushing and Storage . . . . . . . . . . . . . . . . . . . . . . . . . 13
Tightening Threaded Connections . . . . . . . . . . . . . . . 13
Preventive Maintenance Schedule . . . . . . . . . . . . . . . 13
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Repairing the Air Valve . . . . . . . . . . . . . . . . . . . . . . . .15
Ball Check Valve Repair . . . . . . . . . . . . . . . . . . . . . . .17
Diaphragm Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Bearing and Air Gasket Removal . . . . . . . . . . . . . . . . 21
Parts Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Evacuation and transfer pumps . . . . . . . . . . . . . . . . .23
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Repair Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Fluid Section Repair Kit 819.0986 . . . . . . . . . . . . . . . 24
Air Valve Repair Kit 819.4274 . . . . . . . . . . . . . . . . . . .24
Torque Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Evacuation and Transfer Pumps (Model 810.0780) . . 26
Customer Services/Guarantee . . . . . . . . . . . . . . . . . . . . 27

819.0254 3
Symbols
Warning Symbol
Thissymbol alerts youto the possibilityof serious injuryor
death if you do not follow the instructions.
Caution Symbol
This symbol alerts you to the possibility of damage to or
destruction of equipment if you do not follow the
instructions.
Warning Caution
WARNING
INSTRUCTIONS
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture or malfunction and result in serious injury.
• This equipment is for professional use only.
• Read all instruction manuals, tags, and labels before operating the equipment.
• Use the equipment only for its intended purpose. If you are not sure, call your VERDER
distributor.
• Do not alter or modify this equipment.
• Check equipment daily. Repair or replace worn or damaged parts immediately.
• Do not exceed the maximum working pressure of the lowest rated component in your system.
Refer to the Technical Data on page 26 for the maximum working pressure of your equipment.
• Use fluids and solvents which are compatible with the equipment wetted parts. Refer to the
Technical Data section of all equipment manuals. Read the fluid and solvent manufacturer’s
warnings.
• Do not kink or overbend hoses or use hoses to pull equipment.
• Route hoses away from traffic areas, sharp edges, moving parts, and hot surfaces. Do not
expose VERDER hoses to temperatures above 82°C (180°F) or below -40°C (-40°F).
• Wear hearing protection when operating this equipment.
• Do not lift pressurized equipment.
• Comply with all applicable local, state, and national fire, electrical, and safety regulations.
• Never use 1,1,1-trichloroethane, methylene chloride, other halogenated hydrocarbon solvents or
fluids containing such solvents in pressurized aluminum equipment. Such use could result in a
chemical reaction, with the possibility of explosion.

4 819.0254
TOXIC FLUID HAZARD
Hazardous fluid or toxic fumes can cause serious injury or death if splashed in the eyes or on the skin,
inhaled, or swallowed.
• Know the specific hazards of the fluid you are using.
• Store hazardous fluid in an approved container. Dispose of hazardous fluid according to all local,
state and national guidelines.
• Always wear protective eyewear, gloves, clothing and respirator as recommended by the fluid
and solvent manufacturer.
• Pipe and dispose of the exhaust air safely, away from people, animals, and food handling areas.
If the diaphragm fails, the fluid is exhausted along with the air. See Air Exhaust Ventilation on
page 9.
•Never use an acetal pump to pump acids. Take precautions to avoid acid or acid fumes from
contacting the pump housing exterior. Stainless steel parts will be damaged by exposure to acid
spills and fumes.
FIRE AND EXPLOSION HAZARD
Improper grounding, poor ventilation, open flames, or sparks can cause a hazardous condition and
result in a fire or explosion and serious injury.
• Ground the equipment. Refer to Grounding on page 5.
• If there is any static sparking or you feel an electric shock while using this equipment, stop
pumping immediately. Do not use the equipment until you identify and correct the problem.
• Provide fresh air ventilation to avoid the buildup of flammable fumes from solvents or the fluid
being pumped.
• Pipe and dispose of the exhaust air safely, away from all sources of ignition. If the diaphragm
fails, the fluid is exhausted along with the air. See Air Exhaust Ventilation on page 9.
• Keep the work area free of debris, including solvent, rags, and gasoline.
• Electrically disconnect all equipment in the work area.
• Extinguish all open flames or pilot lights in the work area.
• Do not smoke in the work area.
• Do not turn on or off any light switch in the work area while operating or if fumes are present.
• Do not operate a gasoline engine in the work area.
• Keep a fire extinguisher in the work area.
WARNING

819.0254 5
Installation
General Information
• The Typical Installations shown in Fig. 2 to Fig. 4 are
only guides for selecting and installing system
components. Contact your VERDER distributor for
assistance in planning a system to suit your needs.
• Reference numbers and letters in parentheses refer
to the callouts in the figures and the parts lists on
pages 23 to 24.
• Installation and use must be in accordance with the
Flammable and Combustible Liquids Code (NFPA
30) and Automotive and Marine Service Station Code
(NFPA 30A) and must comply with all local, state,
and federal codes.
• All pipe joints are to be made tight with UL listed
gasoline-resistant pipe compound.
Tightening Screws Before First Use
Before using the pump for the first time, check and
retorqueallexternalfasteners.SeeTorque Sequence on
page 25. After the first day of operation, retorque the
fasteners. Although pump use varies, a general guideline
is to retorque fasteners every two months.
Grounding
•Pump: loosen the grounding screw (W). Insert one
end of a 12 ga (1.5 mm2) minimum ground wire (Y)
behind the grounding screw and tighten the screw
securely. See Fig. 1. Connect the clamp end of the
ground wire to a true earth ground. Order Part No.
819.0157 Ground Wire and Clamp.
•Air and fluid hoses: use only grounded hoses with a
maximum of 500 ft (150 m) combined hose length to
ensure grounding continuity.
•Air compressor: follow manufacturer’s
recommendations.
•Solvent pails: Ground all solvent pails used when
flushing, according to local code. Use only metal
pails, which are conductive. Do not place the pail on
a non-conductive surface, such as paper or
cardboard, which interrupts the grounding continuity.
•Fluid supply container: ground according to local
code.
•Suction device nozzle: must be bonded to metal
container from which it is suctioning by firm
metalto-metal contact to a properly grounded suction
hose and pump.
•Piping, valves, and fittings: use only electrically
conductive materials. Bond and ground per code.
Check your system electrical continuity after the initial
installation, and then set up a regular schedule for
checking continuity to be sure proper grounding is
maintained.
Fig. 1
WARNING
FIRE AND EXPLOSION HAZARD
Before operating the pump, ground the
system as explained below. Also read the
section FIRE AND EXPLOSION HAZARD
on page 4.

6 819.0254
Installation
Mountings
• Be sure the mounting surface can support the weight
of the pump, hoses, and accessories, as well as the
stress caused during operation.
• For all mountings, be sure the pump is bolted directly
to the mounting surface.
• For ease of operation and service, mount the pump
so the air valve cover (2), air inlet, and fluid inlet and
outlet ports are easily accessible.
• Rubber Foot Mounting Kit 819.4333 is available to
reduce noise and vibration during operation.
Air Line
1. Install the air line accessories as shown in Fig. 2 to
Fig. 4 on pages 7 and 8. Mount these accessories on
the wall or on a bracket. Be sure the air line supplying
the accessories is grounded.
a. Install an air regulator (C) and gauge to control
thefluidpressure.Thefluidoutletpressureatstall
will be the same as the setting of the air regulator.
b. Locate one bleed-type master air valve (B) close
to the pump and use it to relieve trapped air. See
theWARNINGabove.Locatetheothermasterair
valve (E) upstream from all air line accessories
and use it to isolate them during cleaning and
repair.
c. The air line filter (F) removes harmful dirt and
moisture from the compressed air supply.
2. Install a grounded, flexible air hose (A) between the
accessories and the 1/2 npt(f) pump air inlet (N). See
Fig. 6. Use a minimum 1/2 in. (13 mm) ID air hose.
Screw an air line quick disconnect coupler (D) onto
the end of the air hose (A), and screw the mating
fitting into the pump air inlet snugly. Do not connect
the coupler (D) to the fitting until you are ready to
operate the pump.
CAUTION
The pump exhaust air may contain contaminants.
Ventilate to a remote area if the contaminants could
affectyour fluid supply.See Air Exhaust Ventilation on
page 9.
WARNING
Toreducetheriskofseriousinjury,splashingintheeyes
or on the skin, and toxic fluid spills, never move or lift a
pump under pressure. If dropped, the fluid section may
rupture. Always follow the Pressure Relief Procedure
on page 11 before moving or lifting the pump.
WARNING
A bleed-type master air valve (B) is required in your
system to relieve air trapped between this valve and the
pump. Trapped air can cause the pump to cycle
unexpectedly, which could result in serious injury,
includingsplashing in theeyesor on theskin, injury from
moving parts, or contamination from hazardous fluids.

819.0254 7
Installation
Fig. 2
Fig. 3
KEY FOR FIG. 2
A Air supply line
B Bleed-type master air valve (required
for pump)
C Air regulator
D Air line quick disconnect
E Master air valve (for accessories)
F Air line filter
G Fluid suction line
H Fluid line quick disconnect
J Fluid drain valve (required)
K Fluid shutoff valve
L Fluid line
M Waste oil receiver
Y Ground wire (required; see page 5 for
installation instructions)
Waste Oil Receiver Evacuation System, or
General Fluid Transfer Application
Gear Oil Evacuation System
KEY FOR FIG. 3
A Air supply line
B Bleed-type master air valve (required
for pump)
C Air regulator
D Air line quick disconnect
E Master air valve (for accessories)
F Air line filter
G Fluid suction line
H Fluid line quick disconnect
J Fluid drain valve (required)
K Fluid shutoff valve
L Waste oil line (to storage tank)
P Suction hose
R Control valve
S Suction wand
Y Ground wire (required; see page 5 for
installation instructions)

8 819.0254
Installation
Fig. 4
Pressure Relief Valve (Fuel Dispense
Systems) Changing the Orientation of the Fluid Inlet and Outlet Ports
If desired, you can easily change the orientation of the
fluid inlet and outlet ports. See Fig. 6.
1. Remove the screws (6) holding the inlet and/or outlet
manifold (1, 3) to the covers (2).
2. Reverse the manifold and reattach. Install the screws
and torque to 120 to 150 in–lb (14–17 N•m). See
Torque Sequence on page 25.
KEY FOR FIG. 4
A Air supply line
B Bleed-type master air valve (required
for pump)
C Air regulator
D Air line quick disconnect
E Master air valve (for accessories)
F Air line filter
G Fluid suction line
J Fluid drain valve (required)
K Fluid shutoff valve
L Fluid line
T Hose reel
V Fuel dispense valve
Y Ground wire (required; see page 5 for
installation instructions)
46 Pressure relief valve (required to limit
fluid outlet pressure to 50 psi [350
kPa, 3.5 bar])
Fluid from the relief valve (46) must
be vented to a safe area.
1
Fuel Dispense System
WARNING
Fuel Dispense Model 810.0781 requires a pressure
relief valve 819.0252 (46), which is supplied with the
pump, to prevent fluid pressure from exceeding 50 psi
(350 kPa, 3.5 bar). Do not exceed the maximum air inlet
pressureof 50psi (350 kPa, 3.5 bar).Recommended air
operating pressure is 40 psi (280 kPa, 2.8 bar) or less.
Astheairinletpressureapproaches50psi(350kPa,3.5
bar),the reliefvalve willopen andvent fluid.Vented fluid
must be routed to a container in a safe place.

819.0254 9
Installation
Air Exhaust Ventilation
The air exhaust port is 3/4 npt(f). Do not restrict the air
exhaust port. Excessive exhaust restriction can cause
erratic pump operation.
To provide a remote exhaust:
1. Remove the muffler (U) from the pump air exhaust
port.
2. Install a grounded air exhaust hose (W) and connect
the muffler (U) to the other end of the hose. The
minimum size for the air exhaust hose is 3/4 in. (19
mm) ID. If a hose longer than 15 ft (4.57 m) is
required, use a larger diameter hose. Avoid sharp
bends or kinks in the hose.
3. Place a container (X) at the end of the air exhaust line
to catch fluid in case a diaphragm ruptures. See Fig.
5. Locate the container away from all sources of
ignition, including pilot lights and waste materials. If
the diaphragm ruptures, the fluid being pumped will
exhaust with the air.
VENTING EXHAUST AIR
Fig. 5
WARNING
Be sure to read and follow the TOXIC FLUID HAZARD
and FIRE AND EXPLOSION HAZARD warnings on
page 4 before operating this pump.
Be sure the system is properly ventilated for your type of
installation. You must vent the exhaust to a safe place,
away from people, animals, food handling area, and all
sources of ignition when pumping flammable or
hazardous fluids.
Diaphragm failure will cause the fluid being pumped to
exhaust with the air. Place an appropriate container at
the end of the air exhaust line to catch the fluid. See Fig.
5.
KEY
A Air supply line
B Bleed-type master air valve
(required for pump)
C Air regulator
D Air line quick disconnect
E Master air valve (for accessories)
F Air line filter
U Muffler
W Grounded air exhaust hose
X Container for remote air exhaust

10 819.0254
Installation
Fluid Pressure Relief Kit (for Pump Model 810.0780 only)
Fig. 6
Caution
Pressure Relief Kit 819.6479 (Z) is available, to
preventoverpressurization and rupture of the pump or
hose. See Fig. 6. The kit includes instructions.
Thermal expansion of fluid in the outlet line can cause
overpressurization. This can occur when using long
fluid lines exposed to sunlight or ambient heat, or
when pumping from a cool to a warm area (for
example, from an underground tank).
This kit is not for use in fuel dispense
applications. Order a fuel dispense pump, Model
810.0781, which is equipped with a pressure relief
valve 819.0252. See page 8.
Overpressurization can also occur if the VA 25 pump
is being used to feed fluid to a piston pump, and the
intake valve of the piston pump does not close,
causing fluid to back up in the outlet line.
8
N
U
5
Z
Z
6
4
2653c
2
KEY
1 1 in. npt(f) optional fluid outlet port
2 Fluid covers
3 1 in. npt(f) optional fluid inlet port
6 Manifold and cover screws
8 Air valve screws
N 1/2 in. npt(f) air inlet port
U Muffler; air exhaust port is 3/4 in. npt(f)
Z Pressure relief kit
Apply medium-strength (blue) Loctite or
equivalent to the threads and install kit between
fluid inlet and outlet manifolds.
1
Connect fluid inlet line here.
2
Connect fluid outlet line here.
3
Torque to 120 to 150 in-Ib (14 to 15 N•m).
See Torque Sequence on page 25. Apply
medium-strength (blue) Loctite or
equivalent to the threads.
4
Torque to 50 to 60 in-Ib (5.6 to 6.87 N•m).
5

819.0254 11
Operation
Pressure Relief Procedure
1. Shut off the air to the pump.
2. Open the dispensing valve, if used.
3. Open the fluid drain valve to relieve all fluid pressure,
having a container ready to catch the drainage.
Flush the Pump Before First Use
The pump was tested in water. If water could contaminate
the fluid you are pumping, flush it thoroughly with a
compatible solvent. Follow the steps under Starting and
Adjusting the Pump on page 12.
WARNING
PRESSURIZED EQUIPMENT HAZARD
The equipment stays pressurized until pressure is
manually relieved. To reduce the risk of serious injury
from pressurized fluid, accidental spray from the gun or
splashing fluid, follow this procedure whenever you:
• Are instructed to relieve pressure
• Stop pumping
• Check, clean or service any system equipment
• Install or clean fluid nozzles

12 819.0254
Operation
Starting and Adjusting the Pump
All Systems
1. Be sure the pump is properly grounded. Read and
follow FIRE AND EXPLOSION HAZARD, on page 4.
2. Check all fittings to be sure they are tight. Be sure to
use a compatible liquid thread sealant on all male
threads. Tighten the fluid inlet and outlet fittings
securely.
NOTE: If the fluid inlet pressure to the pump is more than
25 percent of the outlet working pressure, the ball check
valves will not close fast enough, resulting in inefficient
pump operation.
NOTE: If you are flushing, run the pump long enough to
thoroughly clean the pump and hoses. Close the air
regulator. Remove the suction tube from the solvent and
place it in the fluid to be pumped.
Waste Oil Receiver Evacuation Systems, or General
Fluid Transfer Applications (see Fig. 2)
1. Close the pump air regulator (C) and all bleed-type
master air valves (B, E).
2. Connect the pump suction hose (G) to the pump fluid
inlet. Attach a fluid quick coupler (H) to the other end
of the hose, then connect the coupler to the outlet
fitting of the waste oil receiver (M).
3. Place the end of the fluid hose (L) into an appropriate
container.
4. Close the fluid drain valve (J). Open the fluid shutoff
valve (K).
5. Connect the air side quick coupler (D) to the pump air
inlet fitting.
6. Open all bleed-type master air valves (B, E).
7. Slowly increase air with the air regulator (C) until the
pump starts to cycle. Allow the pump to cycle slowly
until all air is pushed out of the lines and the pump is
primed.
8. Adjusttheairregulator. Donotusehigherairpressure
than necessary for the pump to provide good suction.
Increasing the pump cycle rate does not necessarily
improve suction.
Gear Oil Evacuation Systems (see Fig. 3)
1. Close the pump air regulator (C) and all bleed-type
master air valves (B, E).
2. Attach an appropriate wand (S) to the suction hose
(P). Place the wand in the differential or fluid to be
pumped.
3. Place the end of the fluid hose (L) into an appropriate
container.
4. Close the fluid drain valve (J). Open the fluid shutoff
valve (K).
5. Connect the air side quick coupler (D) to the pump air
inlet fitting.
6. Open all bleed-type master air valves (B, E).
7. Set the air regulator (C) to about 50 psi (3.5 bar).
8. Pull the control valve handle (R) down to start the
pump.
9. Adjust the air regulator. Allow the pump to cycle
slowly until all air is pushed out of the lines and the
pump is primed. Do not use higher air pressure than
necessary for the pump to provide good suction.
Increasing the pump cycle rate does not necessarily
improve suction.
10. Push the control valve handle (R) up when finished.
Place the wand (S) in the holder on the control valve.
NOTE: Be sure the control valve handle (R) is closed
when evacuation is completed. Failure to close it may
prevent other service bays from developing full suction.
Pump Shutdown (All Systems)
Attheendof theworkshiftandbeforechecking,adjusting,
cleaning, or repairing the system, relieve the pressure.
WARNING
Toreducetheriskofseriousinjury,splashingintheeyes
or on the skin, and toxic fluid spills, never move or lift a
pump under pressure. If dropped, the fluid section may
rupture. Always follow the Pressure Relief Procedure
on page 11 before moving or lifting the pump.
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.

819.0254 13
Maintenance
Lubrication
The air valve is designed to operate unlubricated. If
lubrication is desired, every 500 hours of operation (or
monthly),removethehose fromthepumpairinletandadd
two drops of machine oil to the air inlet.
Flushing and Storage
Flush the pump often enough to prevent the fluid you are
pumping from drying or freezing in the pump and
damaging it. Always flush the pump and relieve the
pressure before storing it for any length of time. Use a
compatible solvent.
Tightening Threaded Connections
Beforeeachuse,check all hoses forwearordamage,and
replace as necessary. Check to be sure all threaded
connections are tight and leak-free. Check fasteners.
Tighten or retorque as necessary. Although pump use
varies, a general guideline is to retorque fasteners every
two months. See Torque Sequence on page 25.
Preventive Maintenance Schedule
Establish a preventive maintenance schedule, based on
the pump’s service history. This is especially important for
prevention of spills or leakage due to diaphragm failure.
CAUTION
Donotover-lubricatethepump.Oilisexhaustedthrough
themuffler, which couldcontaminate yourfluid supply or
other equipment. Excessive lubrication can also cause
the pump to malfunction.
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.

14 819.0254
Troubleshooting
Relieve the pressure before checking or servicing the
equipment.
Check all possible problems and causes before
disassembling the pump.
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.
PROBLEM CAUSE SOLUTION
Pump cycles at stall or fails to hold
pressure at stall. Worn check valve balls (16) or seats (17). Replace. See page 17.
Pump will not cycle, or cycles once and
stops. Air valve is stuck or dirty. Disassemble and clean air valve. See pages 15 and 16. Use filtered air.
Check valve ball (16) severely worn and
wedged in seat (17) or manifold (1 or 3). Replace ball and seat. See page 17.
Check valve ball (16) is wedged into seat
(17), due to overpressurization. Install Pressure Relief Kit (see page 10).
Dispensing valve clogged. Relieve pressure and clear valve.
Pump operates erratically. Clogged suction line. Inspect; clear.
Sticky or leaking check valve balls (16). Clean or replace. See page 17.
Diaphragm (29) ruptured. Replace. See pages 18 to 20.
Restricted exhaust. Remove restriction.
Pump will not operate. Foreign material in ball checks. Clean ball check area.
Air bubbles in fluid. Suction line is loose. Tighten.
Diaphragm (29) ruptured. Replace. See pages 18 to 20.
Loose manifolds (1, 3), or damaged seal
between manifold and seat (17). Tighten manifold bolts (6) or replace seats (17). See page 17.
Loose diaphragm shaft bolt (21). Tighten. See pages 18 to 20.
Damaged o-ring (25). Replace. See pages 18 to 20.
Fluid in exhaust air. Diaphragm (29) ruptured. Replace. See pages 18 to 20.
Loose diaphragm shaft bolt (21). Tighten. See pages 18 to 20.
Damaged o-ring (25). Replace. See pages 18 to 20.
Pump exhausts excessive air at stall. Wornairvalveblock(13), o-ring (12), plate
(14), pilot block (9), or o-ring (27). Repair or replace. See pages 15 and 16.
Worn shaft seals (22). Replace. See pages 18 to 20.
Pump leaks air externally. Air valve cover (7) or air valve cover
screws (8) are loose. Tighten screws. See page 16.
Air valve gasket (10) or air cover gasket
(32) is damaged. Inspect; replace. See pages 15 and 16, 21 and 22.
Air cover screws (6) are loose. Tighten screws. See pages 21 and 22.
Pumpleaksfluidexternally from ball check
valves. Loose manifolds (1, 3), or damaged seal between manifold and seat (17). Tighten manifold bolts (6) or replace seats (17). See page 17.
Relief valve relieving (Fuel Dispense
Model 810.0781). Air inlet pressure is too high. Reduce inlet air pressure to below 50 psi (3.5 bar).
In evacuation application, pump is not
drawing suction. Pump should run at uniform speed. Reduce inlet air pressure.

819.0254 15
Service
Repairing the Air Valve
Tools Required
• Torque wrench
• Torx (T20) screwdriver or 7 mm socket wrench
• Needle-nose pliers
• O-ring pick
• Lithium base grease
NOTE: Air Valve Repair Kit 819.4274 is available. Refer
to page 24. Parts included in the kit are marked with a
symbol, for example (10†). Use all the parts in the kit for
the best results.
Disassembly
1. Relieve the pressure.
2. With a Torx (T20) screwdriver or 7 mm (9/32 in.)
socket wrench, remove the six screws (8), air valve
cover (7), and gasket (10). See Fig. 7.
3. Move the valve carriage (11) to the center position
and pull it out of the cavity. Remove the valve block
(13) and o-ring (12) from the carriage. Using a
needle-nose pliers, pull the pilot block (9) straight up
and out of the cavity. See Fig. 8.
4. Pull the two actuator pistons (30) out of the bearings
(31). Remove the u-cup packings (22) from the
pistons. Pull the push pins (26) out of the bearings
(28).Removethe o-rings (27) fromthepush pins. See
Fig. 9.
5. Inspect the valve plate (14) in place. If damaged, use
a Torx (T20) screwdriver or 7 mm (9/32 in.) socket
wrench to remove the three screws (8). Remove the
valve plate (14) and seal (15). See Fig. 10.
6. Inspectthe bearings(28, 31) in place. SeeFig. 9. The
bearings are tapered and, if damaged, must be
removed from the outside. This requires disassembly
of the fluid section. See page 21.
7. Clean all parts and inspect for wear or damage.
Replace as needed. Reassemble as explained on
page 16.
Fig. 7
Fig. 8
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.
Torque to 50–60 in-lb
(5.6–6.8 N•m).
2
See Detail at right.
Grease.
Grease lower face.
1
2
3

16 819.0254
Service
Fig. 9 Fig. 10
Reassembly
1. If you replaced the bearings (28, 31), reinstall as
explained on page 21. Reassemble the fluid section.
2. Install the valve plate seal (15) into the groove at the
bottom of the valve cavity. The rounded side of the
seal must face down into the groove. See Fig. 10.
3. Install the valve plate (14) in the cavity. The plate is
reversible, so either side can face up. Install the three
screws (8), using a Torx (T20) screwdriver or 7 mm
(9/32 in.) socket wrench. Torque to 50–60 in-lb (5.6–
6.8 N•m). See Fig. 10.
4. Install an o-ring (27) on each push pin (26). Grease
the pins and o-rings. Insert the pins into the bearings
(28), narrow end first. See Fig. 9.
5. Install a u-cup packing (22) on each actuator piston
(30), so the lips of the packings face the narrow end
of the pistons. See Fig. 9.
6. Lubricate the u-cup packings (22) and actuator
pistons (30). Insert the actuator pistons in the
bearings (31), wide endfirst. Leave the narrow end of
the pistons exposed. See Fig. 9.
7. Install the pilot block (9) so its tabs snap into the
grooves on the ends of the push pins (26). See Fig. 8.
8. Grease the o-ring (12) and install it in the valve block
(13). Push the block onto the valve carriage (11).
Grease the lower face of the valve block. See Fig. 8.
9. Align the valve carriage (11) with the actuator pistons
(30) and install so its tabs slip into the grooves on the
narrow end of the pistons. See Fig. 8.
10. Align the valve gasket (10) and cover (7) with the six
holes in the center housing (5). Secure with six
screws (8), using a Torx (T20) screwdriver or 7 mm
(9/32 in.) socket wrench. Torque to 50–60 in-lb (5.6–
6.8 N•m). See Fig. 7.
Insert narrow end first.
Grease.
Install with lips facing
narrow end of piston (30).
Insert wide end first.
1
2
3
4

819.0254 17
Service
Ball Check Valve Repair
Tools Required
• Torque wrench
• 10 mm socket wrench
• O-ring pick
Disassembly
NOTE: FluidSection RepairKit isavailable. Refer to page
24 to order the correct kit for your pump. Parts included in
thekit aremarked with an asterisk, for example (16*). Use
all the parts in the kit for the best results.
NOTE: To ensure proper seating of the balls (16), always
replace the seats (17) when replacing the balls.
1. Relieve the pressure. Disconnect all hoses.
2. Remove the pump from its mounting.
3. Using a 10 mm socket wrench, remove the four bolts
(6) holding the outlet manifold (1) to the fluid covers
(2). See Fig. 14.
4. Remove the seats (17) and balls (16) from the
manifold.
5. Turnthe pump overand removethe inlet manifold(3).
Remove the seats (17) and balls (16) from the fluid
covers (2).
Reassembly
1. Clean all parts and inspect for wear or damage.
Replace parts as needed.
2. Reassembleinthereverseorder,followingallnotesin
Fig. 14. Be sure the ball checks are assembled
exactly as shown. The arrows (A) on the fluid covers
(2) must point toward the outlet manifold (1).
NOTE : Apply medium-strength (blue) Loctite or
equivalent to the threads, and torque to 120 to 150 in-lb
(14 to 17 N•m). See Torque Sequence on page 25.
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.

18 819.0254
Service
Diaphragm Repair
Tools Required
• Torque wrench
•10 mm socket wrench
• 15 mm socket wrench
• O-ring pick
• Lithium-base grease
Disassembly
NOTE: A Fluid Section Repair Kit is available. Refer to
page 24 to order the correct kit for your pump. Parts
included in the kit are marked with an asterisk, for
example (29*). Use all the parts in the kit for the best
results.
1. Relieve the pressure.
2. Remove the manifolds and disassemble the ball
check valves as explained on page 17.
3. Usinga 10 mm socket wrench, remove the screws (6)
holding the fluid covers (2) to the air covers (4). Pull
the fluid covers (2) off the pump. See Fig. 11.
Fig. 11
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 11.
Apply medium-strength (blue) Loctite or equivalent to the
threads, and torque to 120 to 150 in-lb (14 to 17 N•m). See
Torque Sequence on page 25.
Arrow (A) must point toward air valve (B).
1
2

819.0254 19
Service
4. Loosen but do not remove the diaphragm shaft bolts
(21), using a 15 mm socket wrench on both bolts.
5. Unscrew one bolt from the diaphragm shaft (24) and
remove the o-ring (25), fluid side diaphragm plate
(20), diaphragm (29), and air side diaphragm plate
(20). See Fig. 12.
6. Pull the other diaphragm assembly and the
diaphragm shaft (24) out of the center housing (5).
Remove the bolt (21) from the shaft and disassemble
the remaining diaphragm assembly.
7. Inspect the diaphragm shaft (24) for wear or
scratches. If it is damaged, inspect the bearings (23)
in place. If the bearings are damaged, refer to page
21.
8. Reach into the center housing (5) with an o-ring pick
and hook the u-cup packings (22), then pull them out
of the housing. This can be done with the bearings
(23) in place.
9. Clean all parts and inspect for wear or damage.
Replace parts as needed.
Reassembly
1. Install the shaft u-cup packings (22*) so the lips face
out of the housing (5). Lubricate the packings. See
Fig. 12.
2. Install the diaphragm assembly on one end of the
shaft (24) as follows:
a. Install the o-ring (25*) on the shaft bolt (21).
b. Install the fluid side diaphragm plate (20) on the
bolt so the rounded side faces the diaphragm
(29).
c. Install the diaphragm (29*) on the bolt. Make
certain the side marked AIR SIDE faces the
center housing (5).
d. Install the air side diaphragm plate (20) so the
rounded side faces the diaphragm (29).
e. Apply medium-strength (blue) Loctite or
equivalent to the bolt (21) threads. Screw the bolt
(21) into the shaft (24) hand tight.
3. Grease the length and ends of the diaphragm shaft
(24), and slide it through the housing (5).
4. Assemble the other diaphragm assembly to the shaft
as explained in step 2.
5. Hold one shaft bolt (21) with a wrench and torque the
other bolt to 20 to 25 ft-lb (27 to 34 N•m) at 100 rpm
maximum.
6. Alignthefluid covers (2)andthe center housing(5) so
the arrows (A) on the covers face the same direction
as the air valve (B). Apply medium-strength (blue)
Loctite or equivalent to the threads of the screws (6),
and secure the covers with the screws (6) hand tight.
See Fig. 11. Using a 10 mm socket wrench, torque
the screws oppositely and evenly to 120 to 150 in-lb
(14 to 17 N•m). See Torque Sequence on page 25.
7. Reassemble the ball check valves and manifolds as
explained on page 17.

20 819.0254
Service
Fig. 12
Cutaway View, with Diaphragms in Place Cutaway View, with Diaphragms Removed
Lips face out of housing (5).
Rounded side faces diaphragm (29).
Air side must face center housing (5).
Grease.
Apply medium-strength (blue) Loctite or equivalent.
Torque to 20 to 25 ft-lb (27 to 34 N•m).
1
2
3
4
5