Harbor Freight Tools 92720 User Manual

COMPRESSION TESTER

®

WITH QUICK DISCONNECT

Model 92720

OPERATING INSTRUCTIONS

3491 Mission Oaks Blvd., Camarillo, CA 93011

Visit our Web site at: http://www.harborfreight.com

TO PREVENT SERIOUS INJURY,

READ AND UNDERSTAND ALL WARNINGS

AND INSTRUCTIONS BEFORE USE.

Copyright 2005 by Harbor Freight Tools®. All rights reserved. No portion of this

manual or any artwork contained herein may be reproduced in any shape or form

For technical questions or replacement parts, please call 1-800-444-3353.

©

without the express written consent of Harbor Freight Tools.

PRODUCT SPECIFICATIONS

Item Description

Pressure Scale 0 <-> 300 PSI / 0 <-> 20 BAR .
Air Release Type Push Button R elease.
Gauge D iameter 2-9/16” Diam eter / 2-5/8” Bezel Diameter.
Hose Fitting M-18 x 1.50 (Male, W ith “O” Ring).
Adapter Fitting 7/16” Diam eter x 6” Long / Q uick R elease Rubber

Cone.
Hose Size 1/4” Diam eter x 12” Long.
Accessories Carrying Case.
Unit W eight 1.65 Pounds.

Note: Accuracy of the Gauge is ± 2%.

UNPACKING

When unpacking, check to make sure all the parts shown on the Parts Lists on page 8
are included. If any parts are missing or broken, please call Harbor Freight Tools at the
number shown on the cover of this manual as soon as possible.

SAVE THIS MANU AL

You will need this manual for the safety war nings and precautions, assembly, operating,
inspection, maintenance and cleaning procedures, parts list and assembly diagram.
Keep your invoice with this manual. Write the invoice number on the inside of the front
cover. Keep this manual and invoice in a safe and dr y place for future reference.

GENERAL SAFETY PRECAUTIONS

WARNING!

READ AND UNDERSTAND ALL INSTRUCTIONS

Failure to follow all instructions listed in the following

pages may result in serious injury.

SA VE THESE INSTRUCTIONS

REV 05/05

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 2

GENERAL SAFETY RULES

1. Keep your work area clean and well lit. Cluttered work areas invite accidents.

2. Do not operate tools and equipment in explosive atmospheres, such as in
the presence of flammable liquids, gases, or dust. Tools and equipment
create sparks which may ignite flammables.

3. Keep bystanders, children, and visitors away while operating tools and
equipment. Distractions can cause you to lose control. Protect others in the
work area. Provide barriers or shields as needed.

4. Stay alert. Watch what you are doing, and use common sense when oper-

ating tools and equipment. Do not use tools and equipment while tired or
under the influence of drugs, alcohol, or medication. A moment of inatten-

tion while operating tools and equipment may result in serious personal injury.

5. Dress properly. Do not wear loose clothing or jewelry. Contain long hair.
Keep your hair, clothing, and gloves away from moving parts. Loose
clothes, jewelry, or long hair can be caught in moving parts.

6. Do not overreach. Keep proper footing and balance at all times. Proper
footing and balance enables better control of the tool in unexpected situations.

7. Use safety equipment. Always wear ANSI approved safety impact goggles

when using this product.

8. Do not force the tool. Use the correct tool for your application. The correct
tool will do the job better and safer at the rate for which it is designed.

9. Store idle tools and equipment out of reach of children and other untrained
persons. Tools and equipment are dangerous in the hands of untrained users.

10. Maintain tools with care. Do not use a damaged tool. Tag damaged tools “Do
not use” until repaired.

11. If damaged, have the tool serviced before using. Check for loose screws,
misalignment or binding of moving parts, loose mounting, cracked or broken
parts, and any other condition that may affect its safe operation. Many accidents
are caused by poorly maintained tools.

12. Use only accessories that are recommended by the manufacturer for your
model. Accessories that may be suitable for one tool may become hazardous
when used on another tool.

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 3

13. Tool service must be performed only by qualified repair personnel. Service
or maintenance performed by unqualified personnel could result in a risk of injury.

14. When servicing a tool, use only identical replacement parts. Follow

instructions in the
manual. Use of unauthorized parts or failure to follow maintenance instructions

may create a risk of injury.

“Inspection, Maintenance, And Cleaning”

section of this

SPECIFIC SAFETY RULES

1. WARNING! Do not exceed the maximum pressure capacity of this tool
(300 PSI/20 BAR). Exceeding the maximum pressure capacity could cause

serious personal injury and/or property damage.

2. WARNING! Use the Compression Tester only in well ventilated areas.
A running gasoline engine produces carbon monoxide. Carbon monoxide

fumes are a colorless, odorless, gas that, if inhaled, can cause serious
injury or death.

3. Maintain labels and nameplates on the Compression Tester. These carry
important information. If unreadable or missing, contact Harbor Freight Tools for
a replacement.

4. Prior to using the Compression Tester, make sure to read and understand

all warnings, safety precautions, and instructions as outlined in the
manufacturer’s instruction manual for the engine you will test.

5. When warming up an engine in preparation for compression testing, make
sure the vehicle’s transmission is placed in “PARK”, (or neutral for a
manual transmission) and the emergency brake is applied.

6. Always keep hands and fingers away from the moving parts and hot parts
of the vehicle’s engine.

7. WARNING! The brass components of this product contain lead, a chemi­cal known to the State of California to cause cancer and birth defects (or other
reproductive harm).

8. WARNING! People with pacemakers should consult their physician(s)
before using this product. Electromagnetic fields in close proximity to a heart
pacemaker could cause interference or failure of the pacemaker. In addition,
people with pacemakers should adhere to the following: Caution is necessary
when near the coil, spark plug cables, or distributor of a running engine. The
engine should always be off if adjustments are to be made to the distributor.

(California Health & Safety Code 25249.5 et seq.)

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 4

9. WARNING! The warnings, precautions, and instructions discussed in this
manual cannot cover all possible conditions and situations that may occur. The
operator must understand that common sense and caution are factors, which
cannot be built into this product, but must be supplied by the operator.

OPERATING INSTRUCTIONS

two

1. NOTE: Performing a compression test requires the work of
person to operate the vehicle’s ignition switch while the other person operates
the Compression Tester.

2. The Compression Tester features an Adapter Fitting (2) with its Rubber Cone that
may be used on
used for

14mm

and

all types

of spark plug holes and a Hose Fitting (4) that may be

18mm

spark plug holes. (See Figure A.)

3. To perform a typical compression test, prepare the engine for compression test­ing by starting the engine and allowing it to warm up to its normal operating
temperature. Then, switch off the ignition. WARNING! Avoid carbon monoxide

poisoning! Never run a gasoline engine in an enclosed garage or other
contained area.

individuals; one

4. Once the engine has been turned off, disconnect both coil wires from the coil of
the engine, and remove all of the spark plugs. Note: Insulate coil wires or route
them away from each other and all metal surfaces. Make note of which spark
plug wires go to each spark plug locations. (See Figures B and C, next page.)

GAUGE

(1)

HOSE FITTING

(4)

AIR RELEASE BUTTON

ADAPTER FITTING

(2)

HOSE

(3)

FIGURE A

RUBBER CONE

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 5

5. Attach either the Adapter Fitting (2) or Hose (3) and Hose Fitting (4) to the
Gauge (1). (See Figure A.)

6. Connect the Compression Tester to the first cylinder of the engine. With the fuel
pedal depressed all the way down, crank the engine for at least eight revolutions.

(See Figure C.)

7. While cranking the engine, observe and record the maximum reading on the
Gauge (1) of the Compression Tester. (See Figure C.)

8. Once the maximum reading has been recorded, discontinue cranking the engine.
Then, release the air pressure in the Gauge (1) by pressing the Air Release
Button. (See Figure C.)

9. Remove the Compression Tester from the first engine cylinder. Then repeat
Steps #6, #7, #8 for the remaining engine cylinders. (See Figures B and C.)

10. NOTE: Good engine cylinder compression will be indicated with a high initial
reading, and a progressive build-up to the final maximum reading. Poor engine
cylinder compression will be indicated with a low initial reading, and a much
slower build-up to the final maximum reading. The compression readings for all
of the engine cylinders should not vary by more than 10%. Note: Check your
owner’s or maintenance manual for acceptable pressure ranges.

FIGURE B

REMOVE

SPARK PLUGS

FIGURE C

COIL

COIL WIRES

GAUGE

(1)

AIR RELEASE BUTTON

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 6

INSPECTION, MAINTENANCE, AND CLEANING

1. Before each use, inspect the general condition of the Compression Tester.
Check for broken, cracked, or bent parts, loose or missing parts, and any condi­tion that may affect the proper operation of the product. If a problem occurs,
have the problem corrected before further use.

Do not use damaged equipment.

2. When cleaning, use a clean cloth with a mild detergent. Do not use solvents,
as damage to the Compression Tester may result. Do not immerse the Gauge
(1) in any liquid. Then, store the Compression Tester in a safe, dry location out
of reach of children and other unauthorized people.

3. CAUTION! All maintenance, service, or repairs not listed in this

manual are only to be attempted by a qualified service technician.

PLEASE READ THE FOLLOWING CAREFULLY

THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS LIST AND ASSEMBLY
DIAGRAM IN THIS MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER OR
DISTRIBUTOR MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND TO THE BUYER THAT
HE OR SHE IS QUALIFIED TO MAKE ANY REPAIRS TO THE PRODUCT, OR THAT HE OR SHE IS
QUALIFIED TO REPLACE ANY PARTS OF THE PRODUCT. IN FACT, THE MANUFACTURER AND/OR
DISTRIBUTOR EXPRESSLY STATES THAT ALL REPAIRS AND PARTS REPLACEMENTS SHOULD BE
UNDERT AKEN BY CERTIFIED AND LICENSED TECHNICIANS, AND NOT BY THE BUYER. THE BUYER
ASSUMES ALL RISK AND LIABILITY ARISING OUT OF HIS OR HER REPAIRS TO THE ORIGINAL
PRODUCT OR REPLACEMENT PARTS THERETO, OR ARISING OUT OF HIS OR HER INSTALLATION

OF REPLACEMENT PARTS THERETO.

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 7

PARTS LIST / ASSEMBLY DIAGRAM

#

Part

1 Gauge 1 4 Hose Fitting 1
2 Adapter Fitting 1 5 Carrying Case 1
3 Hose 1

Description Qty. Part # Description Qty.

1

2

4

3

5: CARRYING CASE NOT SHOWN.

NOTE:

Some parts are listed and shown

for illustration purposes only,

and are not available individually

as replacement parts.

SKU 92720 For technical questions please call 1-800-444-3353 PAGE 8