Read Carefully Before Use
Keep for Future Reference
UM-DMG-0024-V2
4-Valve Manifold
Gauge Set
User Manual
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Disclaimer
Read this disclaimer completely and carefully before
proceeding with the rest of the manual content.
1. Product Modifications
Any modifications or alterations to Orion Motor Tech (OMT)
products void any warranties and may result in damage or
injury. OMT shall not be liable for any damages resulting
from such modifications or alterations.
2. Compliance with Laws
Customers shall be liable for ensuring that the use of
OMT products complies with all applicable laws and
regulations in their respective jurisdictions. OMT shall not
be responsible for any violations of laws or regulations
resulting from the use of OMT products.
3. Correct Use
Always use OMT products only as directed in the
accompanying manuals. Failure to follow instructions may
result in injury or damage.
Always ensure the assembly, installation, operation,
maintenance, or repair of OMT products is carried out by
a competent person.
Regular maintenance should be performed throughout
the lifecycle of OMT products. You are responsible for
ensuring the products operate as intended.
Always wear appropriate protective gear.
4. Third-Party Products
OMT shall not be liable for any damages or losses
resulting from the use of third-party products in
conjunction with OMT products. Customers shall refer to
the third-party's guidelines and/or warranties (if any) for
any third-party products used.
5. Limitation of Liability
OMT shall not be liable for any direct, indirect, punitive,
incidental, special, or consequential damages to property
or life, whatsoever arising out of or connected with the
use or misuse of OMT products. In no event shall OMT’s
liability exceed the value of the products sold.
6. Warranty
Refer to the sales page for warranty information.
This disclaimer states the entire obligation of OMT with
respect to OMT products. If any part of this disclaimer is
determined to be void, invalid, unenforceable, or illegal,
including but not limited to the warranty disclaimers, liability
disclaimers, and liability limitations set forth above, the invalid
or unenforceable provision will be deemed superseded by
a valid and enforceable provision that most closely matches
the intent of the original provision and the remainder of the
agreement shall remain in full force and effect.
1
• Read these instructions carefully before use and keep them for future reference. Provide them to anyone who
will use this product and provide them with this product if it is ever given or sold to a third party. Failure to
do so may result in serious property damage and severe personal injury.
• DO NOT allow use by children, individuals with mental or physical conditions that may impair safe operation,
or persons unfamiliar with this product and its compatible air conditioning, fuel, and transmission systems.
• ALWAYS use with proper personal protective equipment such as a dust mask, goggles, and work gloves
in a well-ventilated place, as these refrigerants can irritate your eyes, nose, throat, and skin or cause
frostbite, heart arrhythmia, unconsciousness, and even death. Additionally, operating your vehicle in a closed
environment may result in carbon monoxide poisoning and other problems.
• If you experience symptoms such as headache, dizziness, or nausea while using this product, turn off the
vehicle and seek fresh air IMMEDIATELY. DO NOT continue working until the vehicle has been relocated to
a well-ventilated area.
• ONLY use the coupler marked HIGH on the HIGH-PRESSURE service port. ONLY use the coupler marked
LOW on the LOW-PRESSURE port. Using those interchangeably may cause severe property damage and
serious personal injuries.
• Turn your air-conditioning (A/C) system off before evacuation.
• ONLY use with R1234yf, R134a, or R404a refrigerant and their matching vehicle A/C systems. DO NOT use
the product with other refrigerants or home A/C systems, which can damage this product and your property.
• DO NOT leave this product unattended during use.
• Maintain this product. Check for misalignment, binding, wear, or other damage before use. If any damage is
detected, repair or replace the problematic components before further use. In a large shop, mark such tools
“DO NOT USE” until they have been repaired. ON LY replace components with identical parts.
• ALWAYS perform leak tests on this product and the A/C system before charging. Address any issues
promptly and ensure the system is completely leak-free before proceeding.
• Use EXTREME caution when disconnecting the hoses after use, as they may still contain pressurized
refrigerant.
• Dress appropriately for automotive servicing. DO NOT wear loose clothing or jewelry. Keep hair, clothing,
gloves, hoses, and tools away from moving parts during use.
• In case of an accident or injury, keep a first aid kit and a communication device (e.g., a phone) readily
available. Be familiar with the location of nearby emergency medical facilities.
• Automotive repair is an inherently dangerous activity. This manual and the separate vehicle service manual
cannot cover all possible situations that may arise. ALWAYS exercise discretion and good judgement. Seek
training if needed.
Safety Information
2
Specifications
*
Note: Negative pressure readings are typically measured in inches of mercury (inHg), which
roughly equate to half the value in pounds per square inch (psi) or 1.3% of the value in
centimeters of mercury (cmHg), kilograms per square centimeter (kg/cm²), or bars.
Hoses
Colors
Low-Pressure Blue
High-Pressure Red
Evacuation Black
Charging Yellow
Total Length 5 ft 1.5 m
Thread Dia. 1/4 in
Working Pressure 800 psi 55 bar
Burst Pressure 4000 psi 275 bar
Q u i c k
Couplers
Colors
Low-Pressure Blue
High-Pressure Red
Thread Dia. 1/4 in
Refrigerant
Can Taps
Colors
R1234yf Blue
R134a Red
Thread Dia.
Male Outlet 1/4 in
Female Inlet 1/2 in
Compatible Can Type Self-Sealing
Gauge Set
Overall Dimensions 7.1 × 6.3 × 2.4 in 18 × 16 × 6 cm
Net Weight 2.2 lb. 990 g
Port Thread Dia. 1/4 in.
Pressure
Capacity
Low-Pressure − 15* to 260 psi − 1 to 18 bar
High-Pressure − 15* to 550 psi − 1 to 38 bar
Acceptable Refrigerants R1234yf, R134a, and R404a
3
Package List
Item Name Qty.
A High-Pressure Hose (Red) 1
B Low-Pressure Hose (Blue) 1
C Evacuation Hose (Black) 1
D Evacuation/Charging Hose (Yellow) 1
E Work Gloves 1 Pair
F Gauge Set 1
G
High-Pressure Quick Coupler
(Red, for R134a refrigerant)
1
H
Low-Pressure Quick Coupler
(Blue, for R134a refrigerant)
1
I Dual-Purpose Screwdriver 1
J Valve Core Wrench 1
K
Self-Sealing Can Tap
(Red, for R134a refrigerant)
1
L
Self-Sealing Can Tap
(Blue, for R1234yf refrigerant)
1
Item Name Qty.
M
High-Pressure Quick Coupler
(Red, for R1234yf refrigerant)
1
N
Low-Pressure Quick Coupler
(Blue, for R1234yf refrigerant)
1
O Hose Gaskets 4
P
1/4 ″ Male to 1/2 ″ Female Adapters
(Counterclockwise marked LH and
Clockwise)
2
Q O-Rings 2
R Flat Gaskets 2
S Copper Core 1
Not Included but Helpful:
• Micron Gauge
• Vacuum Pump
• Refrigerant Can
• Nitrogen Source
• Dust Masks
• Goggles
• Tape
• Leak Detector
• Soapy Water
4
Product Diagram
High-Pressure Gauge
For R134a SystemsFor R1234yf Systems
Low-Pressure Gauge
Low-Pressure Valve Knob
Evacuation Valve Knob
Low-Pressure Valve Port
Evacuation Valve Port
Charging Valve Port
Unloading Valve
Charging Valve Port
High-Pressure Valve Knob
High-Pressure Valve Knob
5
Preparation
Charging Valve Port
High-Pressure Valve Knob
Refrigerant can irritate your eyes, nose, throat, and skin or cause frostbite, heart arrhythmia,
unconsciousness, and EVEN death.
Using this product with missing, broken, nonidentical, or unauthorized parts WILL pose a
series of safety hazards.
Clearing Your Work Area
Make sure the work area meets the following conditions:
• No children, bystanders, or pets
• Clean and clear of any clutter or dirt that may affect operation or pose safety hazards
• Well-lit and ventilated but adequately protected from the elements
• Free of explosives and sources of heat such as firecrackers and open flames
Putting on Proper PPE
Hand, breathing, and eye protection are required and should meet the standards by ANSI (American
National Standards Institute) or OSHA (Occupational Safety and Health Administration).
The recommended ones include:
• Work Gloves (D)
• Dust Masks
• Goggles
Checking the Product
After unpacking, check that all items are included and undamaged.
If necessary, ask your local dealer or contractor for new identical replacements.
Familiarizing Yourself with Your A/C Systems
For optimal safety, be sure to know your A/C system and take sufficient training before using this product.
Failures and accidents could happen due to a lack of training.
6
Initial Setup
• Make sure your surroundings ARE safe for using this product.
Avoid operating in crowded, dark, or cluttered areas. Ensure NO explosives or ignition
sources nearby.
• Be sure that ALL connections ARE tightly secured.
• If working on an HVAC system, check that it has been turned off BEFORE starting work.
Note: Wrapping the threads with tape (not included) before making the connection helps
prevent leaks.
Connecting the Hoses to the Gauge
1. Turn the knobs on the gauge set (E) completely clockwise, FULLY closing its low-pressure (LP)
and high-pressure (HP) valves.
2. Unscrew the valve port caps under the knobs, connect the provided hoses to the
corresponding ports by hand, and tighten the connections by hand using the hoses’ locking
nuts. The wrench through the hose helps tighten the locking nut.
• Connect the blue LP hose (B) to the port beside the blue LP knob.
• Connect the red HP hose (A) to the port beside the red HP knob.
• Connect the black evacuation hose (C) to the port below the black evacuation knob (VAC).
DO NOT mix up the three hoses, as they are NOT interchangeable.
Note: Use the hose ends WITHOUT copper cores inside.
7
Connecting the Quick Couplers to the Pressure Hoses
1. Select the quick couplers appropriate for your system.
• Use the couplers marked R1234yf (M and N) for R1234yf refrigerant systems.
• Use the couplers marked R134a (G and H) for R134a refrigerant systems.
For R134a SystemsFor R1234yf Systems
Note:
• If your system uses R404a refrigerant, prepare couplers compatible with your system
and hoses.
• ONLY R1234yf, R134a, and R404a are compatible with the gauge set.
Wrench
Locking Nut
8
2. Connect the blue and red hoses to their identically colored quick couplers, and tighten the
connections by hand using the hoses’ locking nuts.
DO NOT mix up these hoses and couplers, as they are NOT interchangeable.
Note: Use the hose ends WITH copper cores inside.
Copper Core
Locking Nut
For R134a SystemsFor R1234yf Systems
Connecting the Quick Couplers to Your A/C System
1. Hang up the gauge using its hook to ensure optimal safety, stability, and accessibility during
use.
2. Turn the blue and red quick couplers’ knobs completely counterclockwise.
3. Hold one coupler and pull back the sleeve to the knob.
4. Push the coupler onto its matching service port of your A/C system.
Ensure that your A/C system has been turned off.
9
6. Repeat steps 3 − 5 for connecting the other coupler to the A/C system.
•
DO NOT
connect the two couplers to the
INCORRECT
service ports to prevent system
malfunctions and safety hazards.
•
ALWAYS
refer to the instructions and guidelines provided by the manufacturer of your
A/C system for proper installation procedures.
(Example: R1234yf LP Coupler)
5. Release the sleeve to secure the connection. GENTLY pull the coupler to verify the
connection’s security.
(Example: R1234yf LP Coupler)7. Turn the blue and red quick couplers’ knobs
completely clockwise.
10
Operation
You can evacuate your A/C system, and then charge it with refrigerant.
2. Turn on the nitrogen source and set the pressure value.
3. Open the LP and HP valves by turning their knobs SLOWLY counterclockwise.
Performing Leakage Test
1. Connect the yellow hose WITH a copper core inside to a nitrogen source (not included).
The pressure value must NOT exceed your A/C system’s maximum pressure.
Note: Wrapping the threads with tape (not included) before making the connection helps
prevent leaks.
11
4. Once the gauge set indicates the same pressure values as the nitrogen source, close the LP
and HP valves by turning their knobs COMPLETELY clockwise.
5. It is recommended to observe the gauge set for about 15 to 30 minutes to ensure that the
pressure readings remain stable.
If the readings have a significant drop, leakage may exist in the system. Use a leak detector (not
included) to detect leakage and apply soapy water (not included) to locate leakage. Repair or
replace any detected loose joints or worn parts before further use.
12
6. If the pressure readings remain stable and there is no leakage, turn off the nitrogen source
and disconnect the yellow EC hose from the nitrogen source.
7. Open the LP valve by turning its knob (LOW) SLOWLY counterclockwise to release the
nitrogen gas.
8. Once the pressure readings indicate 0 psi, close the two valves by turning their knobs
completely clockwise.
13
• Again, check that your A/C system has been COMPLETELY turned off.
• DO NOT
vent refrigerant to the atmosphere. Use appropriate recovery equipment.
Evacuation
1. Connect a micron gauge (not included) to the E/C port and the yellow hose.
Note: Use the hose end WITHOUT a copper core inside.
14
2. Connect the other end of the yellow hose to a vacuum pump (not included) using its copper
core end.
3. Make sure all connections are tightly
joined and turn the micron gauge
on.
4. Open the LP valve and evacuation
valve by turning their knobs
completely counterclockwise. Turn
on the pump, and the evacuation
begins.
Note:
If the port of your pump does not fit the hose’s 1/4″ threads, use the provided 1/4″
male to 1/2″ female adapter (O) or other suitable adapter to complete the connection.
5. When the micron gauge reads less
than 500 microns, your A/C system
is fully cleared. Close the valves by
turning their knobs COMPLETELY
clockwise and turn off the pump.
6. Disconnect the micron gauge from the gauge set and the black hose. Disconnect the black
hose from the pump.
15
Charging
• ALWAYS keep your refrigerant cans away from heat sources and direct sunlight.
• Be sure NOT to open your refrigerant cans by accident in ANY way.
• Ensure that
BOTH
valves on the gauge ARE completely closed BEFORE starting work.
• NEVER leave your refrigerant cans or the gauge unattended when charging A/C systems.
• ALWAYS wear proper PPE when disconnecting the couplers and hoses after charging is
complete, as they may contain some refrigerant under pressure.
1. Choose a provided self-sealing can tap (J or K) for your refrigerant can as you need.
For R1234yf Refrigerant For R134a Refrigerant
Note:
• Use the red tap (J) for R134a refrigerant cans. Use the blue tap (K) for R1234yf
refrigerant cans.
• Some big refrigerant cans are equipped with taps to regulate the flow of refrigerant.
16
2. Check that the tap has been closed by turning its knob COMPLETELY counterclockwise.
Connect the outlet of the tap to the yellow hose and its inlet to your refrigerant can.
3. Ensure that the yellow hose is connected to the charging port of the gauge set. Turn the tap
knob clockwise to allow the refrigerant to flow through the hose.
(Example: R134a Refrigerant)
Note: Use the hose end WITH a copper core inside.
(Example: R134a Refrigerant)
a
b
c
17
4. Open the LP valve and charging valve by turning their knobs completely counterclockwise and
charging begins.
5. To check if the small refrigerant can is empty, invert the can and GENTLY shake it. If
refrigerant is visible from the glass window, there is still some refrigerant left in the can.
(Example: R134a Refrigerant)
18
9. Disconnect the two quick couplers from your A/C system and take down the gauge set.
7. Consult your A/C system’s specifications to find its recommended pressure, usually between
25–80 psi (1.7–5.5 bars).
8. Once the system reaches the recommended pressure, stop charging the system by turning the
tap knob COMPLETELY counterclockwise, and turning the LP valve knob and charging valve
knob COMPLETELY clockwise.
6. To change the small empty refrigerant can, you MUST close the charging valve by turning
its knob COMPLETELY clockwise and the tap COMPLETELY counterclockwise before
reconnecting a new refrigerant can.
• NEVER discard discarded refrigerant cans at will or put them in ordinary trash cans.
• Discarded refrigerant cans MUST be disposed of in accordance with local waste
disposal regulations.
(Example: R134a Refrigerant)
(Example: R134a Refrigerant)
19
11. Disconnect the hoses from the quick couplers, the tap, and the gauge set.
12. Keep the tap securing on the partially used refrigerant can, or disconnect it from the empty
can or the self-sealing can.
Maintenance
Troubleshooting
Problems Solutions
Pressure readings are unstable or
fluctuating.
Check all connections and seals for leaks. Ensure stable
ambient temperature conditions.
The gauge set displays abnormally
high or low readings.
Check if ambient temperature is affecting the readings.
Inspect for any pressure leaks.
• NEVER scrape the hose or drop the gauge set on hard or rough surfaces.
• Check the parts for misalignment, cracks, and any other conditions that may affect the
operation accuracy before use.
• If any gasket, O-ring, or copper core in the preinstalled refrigerant cap tap, quick coupler, or
any hose is damaged or worn, replace it with its spare part (N, P, Q, or R) using the valve core
wrench (I) and/or dual-purpose screwdriver (H). If any other part of the gauge set is damaged
or worn, have it repaired or replaced before further use.
• Clean the exterior of the gauge set and hoses with a soft damp cloth using a mild detergent
or solvent. DO NOT use harsh abrasives or caustic chemicals.
• Store the gauge set in a clean dry place inaccessible to children and away from direct sunlight
after use.
10. Open the unloading valve by unscrewing its cap to clear any air or vapor remaining inside the
gauge set. Confirm that the pressure readings indicate 0 psi, and then tighten the cap into
place.
User Manual
Rev. 28 Jun. 2025
