Gasboy Gilbarco Global Pumping Unit Operation Manual

Gilbarco® Global Pumping Unit

Operation and Service Manual

MDE-4447A

Computer Programs and Documentation

Federal Communications Commission (FCC) Warning

All Gilbarco Inc. and/or Veeder Root Company computer programs (including software on diskettes and within memory chips) and documentation are copyrighted by, and shall
remain the property of, Gilbarco Inc. and/or Veeder Root Company. Such computer programs and documents may also contain trade secret information. The duplication, disclosure,
modification, or unauthorized use of computer programs or documentation is strictly prohibited, unless otherwise licensed by Gilbarco Inc. and/or Veeder Root Company.

This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency
energy, and if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential
area is likely to cause harmful interference in which case the user will be re quired to correct the inte rference at his own exp ense. Changes or modifications not expressly approved by
the manufacturer could void the user’s authority to operate this equipment.

Approvals

Gilbarco is an ISO 9001:2000 registe red company.
Underwriters Laboratories (UL):

U L File# Products listed with U L

MH1941
MH8467 Transac System 1000 and PAM 1000

All Gilbarco pumps and dispensers that bear
the UL listing mark.

New York City Fire Department (NYFD):

NYFD C of A # Product

4805
4986 Encore and Eclipse

The Advantage Series and
Legacy Series

E105106 Dell DH M M i n i t o w e r
E165027 G-SITE a n d P a s s p o r t S y s t e m s

National Conference of Weights and Measures (NCWM) - Certificate of Conformance (CoC):

Gilbarco pumps and dispensers are evaluated by NCWM under the National Type Evaluation Program (NTEP). NCWM has issued the following CoC:

CoC# Product Model # CoC# Product Model # CoC# Product Model #

02-019 Encore Nxx 02-026 H111B Series AC, RAC 02-034 External Mount CRIND CECXXXXXXX
02-020 Eclipse Exx

02-021

T-12C Console PA0188, RA0188 Fixed Blender
T-12C Console PA0203, RA0203 Dispenser - Low Profile AR, RAR

02-022 T-12G Console PA0180, RA0180

T-15 Console PA0189 Outdoor Card Q11891 G-SITE Keyboard PA0304

02-023

T-15 Controller C2 PA0211 02-029 CRIND — G-SITE Mini Tower PA0301

02-027

02-028

T-15 Controller PA0190
ProBlender AU, RAU TS-1000 Controller PA0241 G-SITE Printer (Citizen) PA0308

02-024

Precision Blender AE, RAE Distribution Box PA0242 02-038 C+ Meter T19976
Dispenser - Standard AK, RAK Micro-T Console PA0250 02-039 Passport PA0324

02-030

Dispenser - Low Profile AL, RAL Meter - EC Series PA024EC10 02-040 Ecometer T20453
Fixed Blender AP, RAF VaporVac Kits CV

02-025

Meter - C Series PA024NC10 02-031 The Advantage Series Bxx, RBxx
Meter - C Series PA024TC10 02-032 Trimline Series AA, RAA
Salesmaker ProBlender AB, RAB 02-033 Meter - C Series PA024XC10

99-165 Salesm a k e r S e r i e s 2 / 2 H /4 /4A AM MPD-A3 Series AD, RAD

MPD-1 Series AN, RAN 02-035 Dimension Dxx

AF, RAF, AG,
RAG

Indoor Card Q11640 G-SITE Distribution Box PA0306

TS-1000 Console PA0240 G-SITE Monitor PA0303

California Air Resources Board (CARB):

Executive Order # Product

G-70-52-AM Balance Vapor Recovery
G-70-150-AE VaporVac

02-036 Legacy Jxxx

G-SITE Printer (Epson) PA0307

02-037

Patents

Gilbarco Inc. products are manufactured or sold under one or more of the following US patents:

Dispensers

4,566,504 4,556,927 4,570,686 4,687,033 4,728,788 4,748,846 4,799,940 4,805,453 4,876,653 4,890,210 4,913,813 4,930,655 4,934,565 4,938,054
4,938,251 4,939,730 4,967,366 4,986,445 5,040,577 5,098,179 5,134,548 5,156,199 5,269,353 5,228,084 5,325,706 5,345,979 5,355,915 5,363,988
5,384,850 5,407,115 5,417,256 5,448,638 5,450,883 5,464,466 5,501,246 5,535,130 5,542,458 5,543,849 5,546,981 5,557,084 5,571,310 5,602,745
5,626,649 5,630,528 5,708,580 5,719,779 5,719,781 5,720,325 5,724,067 5,734,851 5,755,854 5,782,275 5,794,667 5,798,931 5,803,136 5,843,212
5,857,500 5,868,179 5,871,651 5,890,520 5,954,080 5,956,259 5,969,691 5,971,042 5,979,705 5,980,090 6,026,866 6,052,629 6,073,840 6,078,888
6,078,896 6,082,415 6,085,775 6,087,954 6,089,284 6,092,410 6,098,879 6,102,085 6,109,477 6,112,134 6,113,039 6,116,505 6,119,110 6,123,118
6,149,033 6,167,923 6,176,421 6,184,846 6,185,307 6,185,893 6,196,065 6,227,227 6,244,310 6,250,151 6,253,779 6,263,319 6,275,746 6,296,148
6,302,165 6,313,737 6,325,112 6,326,934 6,336,479 6,338,369 6,347,649 6,352,176 6,357,493 6,360,137 6,363,299 6,364,206 6,380,853 6,381,514
6,386,246 6,418,983 6,421,616 6,422,464 6,431,226 6,438,452 6,460,579 6,463,389 6,466,842 6,470,233 6,493,440 6,499,516 6,505,134 6,522,947
6,523,744 6,529,800 6,532,999 6,535,726 6,546,882 6,571,151 6,571,201 6,573,884 6,574,603 6,578,145 6,618,362 6,644,360 6,681,814 6,685,089
6,690,275 6,697,705 6,704,774 6,708,797 6,710,701 6,712,101 6,721,669 6,736,313 6,741,909 6,745,104 6,761,190 6,763,974 6,766,949 RE35,238
D262,971 D265,092 D306,719 D309,144 D316,471 D413,124 D413,311 D413,336 D413,337 D413,610 D413,901 D413,902 D414,192 D414,501
D414,778 D414,779 D414,780 D414,781 D414,782 D415,166 D415,167 D415,168 D415,169 D415,170 D415,171 D415,172 D415,501 D415,777
D416,915 D416,916 D417,226 D418,523 D420,684 D421,612 D422,285 D422,604 D426,555 D428,424 D428,897 D429,739 D429,740 D431,039
D431,252 D431,573 D432,140 D432,141 D432,548 D432,552 D433,031 D433,032 D433,033 D433,034 D433,035 D433,036 D433,037 D433,420
D433,421 D433,422 D433,423 D433,424 D433,685 D433,686 D433,687 D433,688 D434,424 D434,780 D435,051 D440,579 D443,624 D456,820
D457,084

Point of Sale/Back Office Equipment

4,967,366 5,228,084 5,448,638 5,798,931 5,980,090 5,708,580 5,719,779 5,719,781 5,724,067 5,734,851 6,073,840 6,078,888 6,116,505 6,185,307
6,263,319 6,275,746 6,326,934 6,360,137 6,363,299 6,364,206

Trademarks

Non-registered trademarks

™

C-PAM

™

CIM

™

ECR

™

EMC

™

G-CAT

™

Gilbert
G-SITE® Link™SMART CRIND™Val u e L i n e

G-SITE® Lite

This document is subject to change without notice. For information regarding Gilbarco Inc. Literature, call [phone]
E-mail: [e-mail] Internet: http://www.gilbarco.com
© 2008 Gilbarco Inc. All Rights Reserved

™

™

Highline
MultiLine

SMART Meter

™

SmartPad
Optimum™ Series Surge Management System
PAM™ 1000 Tank Monitor

™

PAM

TCR
SMART Connect™Ultra-Hi

SMART
Merchandising

™

™

™

™

™

™

™

Registered trademarks

Dimension® Series The Advantage® Series Encore

®

Gilbarco

™

InfoScreen

®

Legacy
Making Things Better®G-SITE

®

MPD

®

®

Transac

®

Trimline

®

Vap o r Va c

®

Transac® System 1000 Performer

Eclipse
TRIND
Passport
CRIND

e-CRIND

®

®

Additional US and foreign trademarks pending.

®

®

Other brand or product names shown may be

®

trademarks or registered trademarks of their

®

respective holders.

®

Table of Contents

1 – Introduction 1

Purpose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Pumping Unit Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Determining the Model Number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

2 – Important Safety Information 3

3 – Pumping Unit Operation and Maintenance 5

Flow of Liquid Through Pumping Unit and Air Eliminator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Float and Air Separator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Adjustable Bypass Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Air Separator Float Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Control Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Lip Seal Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Pumping Units with Throw-Out Rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

4 – Parts Lists and Kits 11

Model M04920B003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Model M04920B003 - Pumping Unit Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Adjustable Bypass Parts Breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Plug and Fitting Parts Breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Model M04920B015 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Model M04920B015 - Pumping Unit Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Air Eliminator Parts Breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Adjustable Bypass Parts Breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Air Eliminator Float Assembly Parts Breakdown . . . . . . . . . . . . . . . . . . .18

Kits for M04920B003 and M04920B015 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Kit Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Kit Component Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

5 – Troubleshooting 21

General Vacuum and Pressure Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Vacuum Gauge Readings (Inches of Mercury) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Conversion Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Use Gauge Readings to Troubleshoot Self-Contained Dispensers . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Testing Pump Vacuum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Testing Pump Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Troubleshooting Using Gauge Readings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Resolving Problems on Pumping Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

6 – Vapor Lock Causes 31

Reasons for Vapor Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Atmospheric Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Vapor Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008 Page i

Table of Contents

Working Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Measuring Suction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Installation is the Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Vapor Lock Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Page ii MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008

Purpose Introduction

1 – Introduction

Purpose

This manual provides service information regarding mechanical and hydraulic components for
the following Gilbarco Global Pumping Unit models:

• M04920B003 - United States Version, Heavy Duty, (20-24 gpm)

• M04920B015 - European Version, Heavy Duty, (20-24 gpm)

• M04920B011 - United States Version, Alternate Fuel Version, Heavy Duty, (20-24 gpm)

• M04920B012 - European Version, Alternate Fuel Version, Heavy Duty, (20-24 gpm)

Pumping Unit Identification

The following chart shows features of the models covered in this manual.

Where Used

United States M04920B003 X Heavy Duty
Europe M04920B015 X X X X Heavy Duty
United States M04920B011 X Heavy Duty
Europe M04920B012 X X X X Heavy Duty

Model
Number

Heavy

Duty Standard

Revision History

Old Pump Part Number New Pump Part Number

M04920B001 M04920B003
M04920B002 M04920B003
M04920B008 M04920B015
M04920B010 M04920B015

Inlet Check

Valve

Air Vent

Float

Air

Separator

Device

Bypass
Spring

Determining the Model Number

The model number appears on the serial number tag attached to the front of the global
pumping unit. Use the chart under Pumping Unit Identification to determine your model.

MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008 Page 1

Introduction Determining the Model Number

This page is intentionally left blank.

Page 2 MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008

2 – Important Safety Information

Important Safety Information

This section introduces the hazards and safety precautions
associated with installing, inspecting, maintaining or servicing
this product. Before performing any task on this product, read
this safety information and the applicable sections in this
manual, where additional hazards and safety precautions for
your task will be found. Fire, explosion, electrical shock or
pressure release could occur and cause death or serious
injury, if these safe service procedures are not followed.

Preliminary Precautions

You are working in a potentially dangerous environment of
flammable fuels, vapors, and high voltage or pressures. Only
trained or authorized individuals knowledgeable in the related
procedures should install, inspect, maintain or service this
equipment.

Emergency Total Electrical Shut-Off

The first and most important information you must know is
how to stop all fuel flow to the pump/dispenser and island.
Locate the switch or circuit breakers that shut off all power to
all fueling equipment, dispensing devices, and Submerged
Turbine Pumps (STPs).

!

WARNING

!

The EMERGENCY STOP, ALL STOP, and
PUMP STOP buttons at the cashier’s station
WILL NOT shut off electrical po wer to th e pump/
dispenser. This means that even if you activate
these stops, fuel may continue to flow
uncontrolled.

Read the Manual

Read, understand and follow this manual and any other
labels or related materials supplied with this equipment. If you
do not understand a procedure, call a Gilbarco Authorized
Service Contractor or call the Gilbarco Support Center at
1-800-800-7498. It is imperative to your safety and the safety
of others to understand the procedures before beginning
work.

Follow the Regulations

Applicable information is available in National Fire Protection
Association (NFPA) 30A; Code for Motor Fuel Dispensing

Facilities and Repair Garages, NFPA 70; National Electrical
Code (NEC), Occupational Safety and Hazard Association

(OSHA) regulations and federal, state, and local codes. All
these regulations must be followed. Failure to install, inspect,
maintain or service this equipment in accordance with these
codes, regulations and standards may lead to legal citations
with penalties or affect the safe use and operation of the
equipment.

Replacement Parts

Use only genuine Gilbarco replacement parts and retrofit kits
on your pump/dispenser. Using parts other than genuine
Gilbarco replacement parts could create a safety hazard and
violate local regulations.

Safety Symbols and Warning Words

This section provides important information about warning
symbols and boxes.

Alert Symbol

You must use the TOTAL ELECTRICAL SHUT­OFF in the case of an emergency and not the
console’s ALL STOP and PUMP STOP or
similar keys.

To tal Electrical Shut-Off Before Access

Any procedure that requires access to electrical components
or the electronics of the dispenser requires total electrical
shut off of that unit. Understand the function and location of
this switch or circuit breaker before inspecting, installing,
maintaining, or servicing Gilbarco equipment.

Evacuating, Barricading and Shutting Off

Any procedure that requires access to the pump/dispenser or
STPs requires the following actions:

• An evacuation of all unauthorized persons and vehicles
from the work area

• Use of safety tape, cones or barricades at the affected
unit (s)

• A total electrical shut-off of the affected unit (s)

This safety alert symbol is used in this manual and
on warning labels to alert you to a precaution which must be
followed to prevent potential personal safety hazards. Obey
safety directives that follow this symbol to avoid possible
injury or death.

Signal Words

These signal words used in this manual and on warning
labels tell you the seriousness of particular safety hazards.
The precautions below must be followed to prevent death,
injury or damage to the equipment:

DANGER: Alerts you to a hazard or unsafe practice

!

which will result in death or serious injury.

WARNING: Alerts you to a hazard or unsafe practice

!

that could result in death or serious injury.

CAUTION with Alert symbol: Designates a hazard or

!

unsafe practice which may result in minor injury.
CAUTION without Alert symbol: Designates a hazard
or unsafe practice which may result in property or
equipment damage.

Working With Fuels and Electrical Energy

Prevent Explosions and Fires

Fuels and their vapors will explode or burn, if ignited. Spilled
or leaking fuels cause vapors. Even filling customer tanks will
cause potentially dangerous vapors in the vicinity of the
dispenser or island.

MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008 Page 3

Important Safety Information

No Open Fire

Open flames from matches, lighters, welding

torches or other sources can ignite fuels and their vapors.

No Sparks - No Smoking
Sparks from starting vehicles, starting or using power tools,
burning cigarettes, cigars or pipes can also ignite fuels and
their vapors. Static electricity, including an electrostatic
charge on your body, can cause a spark sufficient to ignite
fuel vapors. Every time you get out of a vehicle, touch the
metal of your vehicle, to discharge any electrostatic charge
before you approach the dispenser island.

Working Alone

It is highly recommended that someone who is capable of
rendering first aid be present during servicing. Familiarize
yourself with Cardiopulmonary Resuscitation (CPR) methods,
if you work with or around high voltages. This information is
available from the American Red Cross. Always advise the
station personnel about where you will be working, and
caution them not to activate power while you are working on
the equipment. Use the OSHA Lockout/ Tagout procedures. If
you are not familiar with this requirement, refer to this
information in the service manual and OSHA documentation.

Working With Electricity Safely

Ensure that you use safe and established practices in
working with electrical devices. Poorly wired devices may
cause a fire, explosion or electrical shock. Ensure that
grounding connections are properly made. Take care that
sealing devices and compounds are in place. Ensure that you
do not to pinch wires when replacing covers. Follow OSHA
Lockout/T agout requirements. S t ation employees and service
contractors need to understand and comply with this program
completely to ensure safety while the equipment is down.

Hazardous Materials

Some materials present inside electronic enclosures may
present a health hazard if not handled correctly. Ensure that
you clean hands after handling equipment. Do not place any
equipment in the mouth.

!

WARNING

The pump/dispenser contains a chemical known to the
State of California to cause cancer.

In an Emergency

Inform Emergency Personnel

Compile the following information and inform emergency
personnel:

• Location of accident (for example, address, front/back of
building, and so on)

• Nature of accident (for example, possible heart attack, run
over by car, burns, and so on)

• Age of victim (for example, baby, teenager, middle-age,
elderly)

• Whether or not victim has received first aid (for example,
stopped bleeding by pressure, and so on)

• Whether or not a victim has vomited (for example, if
swallowed or inhaled something, and so on)

WARNING

!

Gasoline ingested may cause unconsciousness
and burns to internal organs.
Do not induce vomiting.
Keep airway open.
Oxygen may be needed at scene.
Seek medical advice immediately.

WARNING

!

Gasoline inhaled may cause unconsciousness
and burns to lips, mouth and lungs.
Keep airway open.
Seek medical advice immediately.

WARNING

!

Gasoline spilled in eyes may cause burns to eye
tissue.
Irrigate eyes with water for approximately 15
minutes.
Seek medical advice immediately.

WARNING

!

Gasoline spilled on skin may cause burns.
Wash area thoroughly with clear water.
Seek medical advice immediately.

IMPORTANT: Oxygen may be needed at scene if gasoline
has been ingested or inhaled. Seek medical advice
immediately.

WARNING

!

Lockout/Tagout

Lockout/Tagout covers servicing and maintenance of

The pump/dispenser contains a chemical known to the
State of California to cause birth defects or other
reproductive harm.

machines and equipment in which the unexpected
energization or start-up of the machine(s) or equipment or
release of stored energy could cause injury to employees or
personnel. Lockout/Tagout applies to all mechanical,
hydraulic, chemical or other energy, but does not cover
electrical hazards. Subpart S of 29 CFR Part 1910 - Electrical
Hazards, 29 CFR Part 1910.333 contains specific Lockout/
Tagout provision for electrical haza rd s.

Page 4 MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008

Flow of Liquid Through Pumping Unit and Air Eliminator Pumping Un it Operation and Maintenance

3 – Pumping Unit Operation and Maintenance

Flow of Liquid Through Pumping Unit and Air Eliminator

The Model M04920 Pumping Unit moves the product from the storage tank to the vehicle or
container in the following manner:

Note: The numbers within parentheses in the procedural steps below refer to the numbers in

Figure 3-1.

1 The fuel is drawn from the storage tank through the strainer screen or filter (1).
2 The rotary vane pumping unit (2) pressurizes the fluid.
3 Fuel enters the centrifugal air separator assembly (3). Any air that is present is forced out of

the air tube along with a small amount of liquid into the atmospheric chamber.

4 When the liquid level in the chamber lifts the float and valve assembly (4), the liquid collected

in the atmospheric chamber is returned to the pump intake. Air is then vented to the
atmosphere through the end tube (5).

5 Air-free fuel leaving the air separator opens the control valve (6) and is pumped into the meter.

The control valve includes a built-in relief valve (7) which relieves excess pressure caused by
hot weather expansion.

6 Fuel passes through the meter where it is accurately measured, then through the hose and

nozzle to the vehicle or container being fueled.

7 Whenever the nozzle is not fully opened, some liquid is relieved into the pump through the

bypass valve (8).

Figure 3-1: Flow Diagram

Vent Tube

Atmospheric
Chamber

Discharge

Pressure
Relief
Valve

Inlet

MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008 Page 5

Pumping Unit Operation and Maintenance Float and Air Separator

Float and Air Separator

IMPORTANT INFORMATION

Before gasoline can be accurately measured by the meter, air and vapors must be eliminated.

The pumping unit eliminates air and vapor by using the air separator and float assembly. The
float assembly employed is as shown in Figure 3-2.

Figure 3-2: Float Assembly

Enlarge Top Hole to
7/16 inch

Flat Side Pointing
Away from Float

Adjustable Bypass Valve

The pumping unit uses an adjustable bypass valve assembly in order to limit the pumping unit
pressure when the motor is running and no fuel is being dispensed. The adjustable bypass
assembly includes the following:

• Valve spring

•Guide

•Cover

• Adjustment screw

• Brass cap

Note: The same bypass assembly is used on all pumping units. See Figure 3-3.

Figure 3-3: Bypass Valve

Page 6 MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008

Air Separator Float Device Pumping Unit Operation and Maintenance

Air Separator Float Device

On OIML Euro versions of the pumping unit, a float assembly is provided on the pumping unit
vent opening. This assembly is used to prevent liquid from escaping through the vent pipe. See

Figure 3-4.

Figure 3-4: Air Separator Float Device

Control Valve

The pumping unit uses a control valve that aids in the elimination of air by producing a back
pressure and is also used as a check valve for any fuel above it.

The control valve also contains a pressure relief valve. This valve relieves excess hose
pressure, which may result from the expansion of fuel in the hose during hot weather, to the air
eliminator chamber. This action prevents hoses from bursting and helps prevent pumping unit
leaks.

Figure 3-5: Control Valve

MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008 Page 7

Pumping Unit Operation and Maintenance Lip Seal Replacement

Lip Seal Replacement

To replace the lip seal, proceed as follows:

1 Remove the belt, pulley, and shaft key.
2 Remove the three screws that hold the seal retainer. See Figure 3-6. Carefully pry the old seal

from the recess in the cover plate.

Note: Do not scratch the shaft.

3 Wipe the shaft clean.
4 With a small plastic plug tool (furnished with new seal), slip the new seal over the shaft.

Remove the tool.

5 Reinstall the seal retainer screws, key, pulley, and belt.

Figure 3-6: Lip Seal Replacement

Stator

Seal
Retainer

Remove Plastic Plug
After Assembling Lip
Seal to Rotor Shaft

Lip
Seal

Screw

Inner
Seal

A 52 5702

Page 8 MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008

Pumping Units with Throw-Out Rings Pumping Unit Operation and Maintenance

Pumping Units with Throw-Out Rings

All pumping units have rotors with throw-out rings and carbon blades.

Note: Studies conclude that pumping units with throw-out rings produce greater vacuum and

are more resistant to vapor lock.

To replace blades in rotors with throw-out rings, proceed as follows:

1 Install throw-out rings in the recesses of the rotor.
2 Install the rotor in the stator assembly.
3 Rotate the rotor until a blade slot is at the 12:00 o'clock position. Install a blade.
4 Rotate the rotor two slots from the installed blade. Ensure that the second slot is at the 12:00

o'clock position. Install a blade.

5 Repeat step 4 for the third blade.
6 Repeat steps 1 to 3 for the three remaining blades. See Figure 3-7.

Figure 3-7: Pumping Units with Throw-Out Rings

Blade Slot at 12:00 o’clock Position

Throw-out Rings

Stator

Rotor and Shaft
Assembly

MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008 Page 9