signs of wear

DETECTING SIGNS OF WEAR

WHERE ARE YOU EXPERIENCING TROUBLE?

While wear and tear are a normal part of owning and operating a vehicle, you may need internal or external repairs every once in a while. Let’s try to identify potential issues you may have with your vehicle.

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UNDER THE HOOD
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INSIDE THE CAB
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OUTSIDE OR REAR OF VEHICLE
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BENEATH THE VEHICLE

UNDER THE HOOD

SLOW RESPONSE TO ACCELERATION?
ENGINE SPUTTERING?
VEHICLE CONSUMING TOO MUCH OIL?

SCHEDULE SERVICE

Keeping up with preventative maintenance can help reduce wear and tear of your engine and other components that can extend the life of your vehicle. If you’re experiencing any of the below issues, it could be related to your ignition, battery, driveline, or powertrain. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Ignition & Battery and Driveline & Powertrain sections below.

UNDER THE HOOD

SLOW RESPONSE TO ACCELERATION?
ENGINE SPUTTERING?
VEHICLE CONSUMING TOO MUCH OIL?

SCHEDULE SERVICE

Keeping up with preventative maintenance can help reduce wear and tear of your engine and other components that can extend the life of your vehicle. If you’re experiencing any of the below issues, it could be related to your ignition, battery, driveline, or powertrain. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Ignition & Battery and Driveline & Powertrain sections below.

INSIDE THE CAB

STRONG ODOR PRESENT?
LOUD RATTLING?
HARD STEERING?
EXCESSIVE VEHICLE BOUNCE?

SCHEDULE SERVICE

There are a lot of parts that have to come together to make steering your vehicle safe and easy. If you’re experiencing any of the above issues, it could be related to your HVAC, suspension, or steering parts. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Suspensions and Steering Parts sections below.

INSIDE THE CAB

STRONG ODOR PRESENT?
LOUD RATTLING?
HARD STEERING?
EXCESSIVE VEHICLE BOUNCE?

SCHEDULE SERVICE

There are a lot of parts that have to come together to make steering your vehicle safe and easy. If you’re experiencing any of the above issues, it could be related to your HVAC, suspension, or steering parts. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Suspensions and Steering Parts sections below.

OUTSIDE OR REAR OF VEHICLE

UNEVEN TIRE WEAR?
FLICKERING BRAKE LIGHTS?
TRUNK NOT LATCHING?
OTHER ISSUES?

SCHEDULE SERVICE

While some concerns with your vehicle may be more obvious than others, some issues are harder to diagnose on your own. If you’re experiencing any of the below issues, it could be related to a larger problem. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Additional Symptoms sections below.

OUTSIDE OR REAR OF VEHICLE

UNEVEN TIRE WEAR?
FLICKERING BRAKE LIGHTS?
TRUNK NOT LATCHING?
OTHER ISSUES?

SCHEDULE SERVICE

While some concerns with your vehicle may be more obvious than others, some issues are harder to diagnose on your own. If you’re experiencing any of the below issues, it could be related to a larger problem. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Additional Symptoms sections below.

BENEATH THE VEHICLE

BRAKES SQUEAKING OR GRINDING?
RADIATOR LEAKING?
TRANSMISSION FLUID LEAKING?
SHIFTING DELAYS?

SCHEDULE SERVICE

If you have a reason to believe your vehicle may have transmission or brake issues, it’s important to catch them early before they evolve into a larger problem. If your vehicle is experiencing any of the below symptoms, it could be related to your brakes, HVAC, or engine cooling. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Brakes and HVAC & Engine Cooling sections below.

BENEATH THE VEHICLE

BRAKES SQUEAKING OR GRINDING?
RADIATOR LEAKING?
TRANSMISSION FLUID LEAKING?
SHIFTING DELAYS?

SCHEDULE SERVICE

If you have a reason to believe your vehicle may have transmission or brake issues, it’s important to catch them early before they evolve into a larger problem. If your vehicle is experiencing any of the below symptoms, it could be related to your brakes, HVAC, or engine cooling. Our GM technicians are your best source for expert help with these GM systems.

 

If you want a more comprehensive list of symptoms, check out the Brakes and HVAC & Engine Cooling sections below.

SYMPTOM GUIDE

SYMPTOM GUIDE

HVAC & ENGINE COOLING

Accumulator
The Accumulator in your vehicle stores low pressure vapor refrigerant that is exiting the evaporator. The Accumulator is used to prevent any liquid refrigerant from reaching the compressor. If liquid refrigerant were to enter the compressor, it could cause damage, as the compressor is not designed to pump liquid, only vapor. The Accumulator also contains desiccant. Desiccant’s function is to absorb moisture that may have entered the AC system. Moisture can get into the AC system during manufacturing, service or from the vehicle operating in humid climates.

Receiver Drier
The Receiver Drier in your vehicle stores high pressure liquid refrigerant and oil that is exiting the condenser. The Receiver Drier contains a material called desiccant. Desiccant’s function is to absorb moisture that may have entered the AC system. Moisture can get into the AC system during manufacturing, service or from the vehicle operating in humid climates.

Signs of Wear:
Lack of or insufficient cooling in cabin

Compressor
The compressor compresses refrigerant. The compression leads to a change in the refrigerant’s boiling point, which helps create the cold air that is delivered through the HVAC system.

Signs of Wear:
Lack of or insufficient cooling
Excessive clicking sounds
Unusual noises during AC operation

Water Pump
The water pump is responsible for circulating engine coolant through the radiator, heater core, and engine system to help maintain optimal engine operating temperatures.

Signs of Wear:
Engine overheating
Leaking coolant

Condenser
The condenser cools high pressure vapor refrigerant into a liquid refrigerant.

Signs of Wear:
Reduced cooling capacity in the vehicle cabin due to physical damage or debris blocking airflow through the condenser.

Compressor Clutch
A critical component of the HVAC system, the compressor clutch engages and disengages the compressor.

Signs of Wear:
Reduced cooling in vehicle interior
Noise when running AC system
Rubbing/grinding noise when AC is off

Blower Motor
Your vehicle’s blower motor drives air through the HVAC system and into the cabin.

Signs of Wear:
Lack of or diminished airflow through cabin vents
Unusual noises coming from blower motor

Engine-Cooling Fan
The engine-cooling fan, located behind the radiator, draws cool outside air through the condenser and radiator at a low-speed to cool the engine.

Signs of Wear:
Engine overheats
Fan doesn’t turn
Poor AC performance

Expansion Valve
The expansion valve restricts the flow of refrigerant, allowing it to change from a high-pressure liquid to a low-pressure liquid.

Signs of Wear:
Lack of cooling in cabin

Evaporator
Warm air from inside your vehicle is delivered to the evaporator. The warm air passes through the evaporator changing the refrigerant state from a low-pressure liquid to a low-pressure gas. Moisture and heat are then removed from the air and returned to the cabin.

Signs of Wear:
Lack of cooling in cabin

Heater Core
Hot engine coolant from the cooling system circulates through the heater core to provide warm air to the passenger compartment.

Signs of Wear:
Sweet smell coming from vents
Insufficient heat from vents
Wet carpet on passenger side

Radiator
Engine coolant flowing through the radiator is cooled by the radiator fan and airflow while driving, to help keep the engine within proper operating temperatures.

Signs of Wear:
Leaking (often a bright green color)
Engine overheats
Sweet smell

Thermostat
The thermostat regulates the temperature of the engine coolant to maintain proper engine operating temperature.

Signs of Wear:
Engine overheats
Engine does not heat up
Reduced fuel economy
Insufficient heat in cabin

IGNITION & BATTERY

Alternator/Generator
Your vehicle’s alternator/generator provides power to the electrical systems and charges the battery while the vehicle is running.

Signs of Wear:
Engine won’t turn over
Loss of battery charge
Some loss of electrical power
Alternator or generator warning light illuminates
Dim headlights

Ignition Coil
The ignition coil increases the electrical system voltage to help ignite the air/fuel mixture.

Signs of Wear:
Engine turns over but won’t start
Engine misfiring especially when damp

Ignition Wire Set
This specialized wire set carries voltage from the ignition coil or electronic coil pack to the spark plugs.

Signs of Wear:
Excessive crank time starting engine
Engine misfiring especially when damp
Visible cracks in wires or boots

Starting Motor & Solenoid
When starting the engine, the solenoid is energized, which engages the starter pinion into the flywheel, while the starter motor drives the pinion to crank the engine.

Signs of Wear:
Poor starting qualities, including repeated starting attempts and key cycles
Grinding while cranking
Intermittent starter engagement while trying to start the engine

Battery
Your vehicle’s battery supplies and stores electrical energy from the alternator or generator when the vehicle’s engine is running. The vehicle battery provides energy to start the engine, plus supplies power to the accessories when the engine is not running. For the best combination of longevity, power, and price, we proudly offer a wide range of ACDelco batteries.

Signs of Wear:
Slow cranking or starter clicking noise
Weak/dim lights while cranking

Spark Plug
Spark plugs provide the spark that ignites the air/fuel mixture within an engine’s cylinders.

Signs of Wear:
Lack of power or misfire/backfire
Sluggish acceleration
Poor fuel economy

FUEL & ENGINE EMISSIONS

Modular Fuel Pump/Sender:
A fuel pump draws fuel from the fuel tank to supply fuel to the fuel injection system. The fuel level sensor or sending unit provides the engine control module with fuel level information which the control module uses to control the fuel gauge.

Signs of Wear:
Engine cranks but does not start
Hard start
Hesitation or stalling
Lack of power
Intermittent power loss
Fuel gauge inaccurate or inoperative

Engine-Control Module (ECM)
This module monitors and synchronizes the operation of the ignition, emission, and fuel-injection systems. All sensors input information to the ECM to constantly adjust the air/fuel mixture for optimum emissions, drivability, and performance.

Signs of Wear:
Engine cranks but does not start
Lack of power or sluggish engine
“Service Engine Soon” light illuminates

Exhaust Gas Recirculation (EGR) Valve
The EGR valve recirculates some of the engine’s exhaust gas back into the intake manifold to be reburned, reducing emissions.

Signs of Wear:
Engine misfire or rough-running
Spark knock (detonation) – Gas engine only
Engine hesitation or stalling
Poor fuel economy
Black smoke from exhaust
“Service Engine Soon” light illuminates

Fuel Injector
The fuel injector sprays a fine mist of fuel into the vehicle’s intake manifold or cylinders. The engine control module controls the injector and ignition timing to achieve optimum emissions, drivability, and performance.

Signs of Wear:
Engine misfire
Lack of power or sluggish engine performance
“Service Engine Soon” light illuminates

Mass Airflow Sensor
This sensor measures the amount of air entering the engine.

Signs of Wear:
Engine hesitation or stalling
Black smoke from exhaust
Poor fuel economy
Hard start
Lack of power or sluggish engine
“Service Engine Soon” light illuminates

Oxygen Sensor
An oxygen sensor monitors the amount of oxygen in the exhaust gas. The amount of oxygen in the exhaust gas is a good indicator of engine combustion efficiency.

Signs of Wear:
Engine misfire or rough-running
Black smoke from exhaust
Poor fuel economy
“Service Engine Soon” light illuminates

Engine Coolant Temperature Sensor
The sensor is an engine management system sensor that is used to monitor the temperature of the engine coolant.

Signs of Wear:
Engine overheating
Black smoke from exhaust
Cooling fan(s) on high-speed all the time
Poor fuel economy
Temperature gauge inaccurate or inoperative – if equipped
“Service Engine Soon” light illuminates

Intake Air-Temperature Sensor
The sensor monitors the temperature of the air entering the engine.

Signs of Wear:
Poor fuel economy
“Service Engine Soon” light illuminates

Humidity Sensor
The sensor monitors the humidity of the air entering the engine.

Signs of Wear:
“Service Engine Soon” light illuminates

Knock Sensor
The knock sensor system enables the engine control module to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation, also known as spark knock.

Signs of Wear:
Spark knock (detonation) – Gas engine only
Lack of power
“Service Engine Soon” light illuminates

Throttle Body and Throttle-Position Sensor
The throttle body is the part of the air intake system that controls the amount of air flowing into the engine, in response to driver accelerator pedal input.

A throttle position (TP) sensor is mounted to the side of the throttle body and is used to monitor the position of the throttle body valve.

Signs of Wear:
Hesitation or stalling
Lack of power
Engine misfire or rough-running
“Reduced Engine Power” light illuminates
“Service Engine Soon” light illuminates

Accelerator Pedal-Position Sensor
The accelerator pedal sensor transmits the position of the accelerator pedal to the engine control module. Based on this information, the control module will open the throttle body valve accordingly.

Signs of Wear:
“Reduced Engine Power” light illuminates
“Service Engine Soon” light illuminates

Fuel Pressure Sensor
Constantly measures the fuel pressure in the fuel rail or fuel line so the ECM can maintain the pressure at optimum levels.

Signs of Wear:
Lack of power or sluggish
“Service Engine Soon” light illuminates

Fuel Composition Sensor
On vehicles equipped to run on E85 ethanol, this sensor constantly measures the amount of ethanol in the fuel.

Signs of Wear:
“Service Engine Soon” light illuminates

Positive Crankcase Ventilation (PCV) Valve
The PCV system removes harmful vapors from the engine and prevents those vapors from being expelled into the atmosphere. The PCV system does this by using engine vacuum to draw vapors from the crankcase into the intake manifold.

Signs of Wear:
Rough-running
Hesitation or stalling
Oil leaks
“Service Engine Soon” light illuminates

Catalytic Converter
The catalytic converter is an emission-control device added to the engine exhaust system to reduce hydrocarbons, carbon monoxide, and nitrogen-oxide pollutants from the exhaust gas.

Signs of Wear:
Engine cranks but does not start
Rough-running
Hesitation or stalling
Lack of power or sluggish
“Service Engine Soon” light illuminates

Resonator
Some exhaust systems are equipped with a resonator. The resonator, located either before or after the muffler, allows the use of mufflers with less back pressure. Resonators are used when vehicle characteristics require specific exhaust tuning.

Signs of Wear:
Exhaust is louder
Clunking noise in rear of vehicle

Muffler & Tailpipe
The exhaust muffler reduces the noise levels of the engine exhaust by the use of tuning tubes. The tuning tubes create channels inside the exhaust muffler that lower the sound levels created by the combustion of the engine. The tailpipe carries the exhaust gases from the muffler to the rear of your vehicle.

Signs of Wear:
Exhaust is louder
Clunking noise in rear of vehicle

DRIVELINE & POWERTRAIN

Wheel Bearing
The wheel bearing is mounted on a wheel hub, which, in turn, is connected to the axle. The bearing reduces friction and increases your control of the vehicle as the wheel turns over the surface of the road.

Signs of Wear:
Grinding
Whining or squealing noises
Looseness or roughness felt in the steering wheel

CV Joint/Boot
The CV boot protects the CV joint of a front or rear half shaft from harmful moisture, sand, dust, and other roadway debris, while maintaining the lubricant inside the joint. If the boot is worn or damaged, these particles can eat away at the CV joint, potentially causing the need to replace the CV joint or even a half shaft.

Signs of Wear:
Lubricant leak
Clicking sounds during turning
Clunking during acceleration
Front-end vibrations

Engine
The engine is the heart of your vehicle. Most engines use combustion (igniting an air/fuel mixture to create mechanical energy) to create power that is delivered to the wheels, which, in turn, propels the vehicle.

Signs of Wear:
Rough running
High oil or fuel consumption
Visible smoke while engine is running

Transmission/Transaxle
The transmission/transaxle in your vehicle uses a combination of hydraulics and gears to transfer power from the engine to the wheels. Transmissions are utilized in rear-wheel-drive applications and transaxles on front-wheel-drive applications.

Signs of Wear:
Noticeable transmission/transaxle slippage
Lack of acceleration
Transmission fluid emits a burning odor

Solid Axle Assembly
The solid axle assembly includes internal components such as the ring and pinion gears, as well as differential, that deliver power to the wheels.

Signs of Wear:
Clanking noise
Whining or humming noise at steady speed or during coast-down

Flywheel
This round, multi-toothed disc connects the engine, clutch system, and automatic transmission.

Signs of Wear:
Noticeable transmission slippage
Lack of acceleration
Failure to engage
Erratic transmission operation

Clutch
Manual vehicles use this combination of components to engage and disengage the engine to and from the transmission for changing gears.

Signs of Wear:
Clutch slippage
Clutch engage failure

SUSPENSION

Shocks & Struts
The ride and handling system is what supports your vehicle’s weight. This system includes shocks and/or struts that keep the tires in contact with the road and help provide a comfortable ride.

Signs of Wear:
Excessive ball joint play
Leaking oil along the shock body
Broken mounts or mounting hardware
Worn or missing bushings
Excessive vehicle bounce
Cupped tire wear

Strut Mount/Bearing
The strut mount helps improve strut operation by absorbing energy and restoring smooth steering, while the bearing allows the strut to turn with the wheels while steering.

Signs of Wear:
Suspension noise
Uneven tire wear
Steering wheel does not easily return to center position

Ball Joint
The ball joint is a pivot point for the tire and wheel assembly, allowing them to turn and move up and down with the suspension.

Signs of Wear:
Rough ride
Play in steering wheel
Slow or stiff steering-wheel return
Excessive tire wear on one side

Coil Springs
Your suspension system’s coil springs support the weight of your vehicle and maintain vehicle ride height.

Signs of Wear:
Low vehicle ride height
Rough, unstable, or uncontrollable ride
Excessive tire wear on one side

Bushings
The bushings attached to the suspension system provide a link between the suspension links or control arms and the chassis.

Signs of Wear:
Excessive steering-wheel play
Hard steering
Noise
Wobble
Irregular tire wear

Control Arm
The control arms join the knuckle which support the tire and wheel assembly to the vehicle frame, allowing for a full range of motion while maintaining proper wheel alignment.

Signs of Wear:
Uneven tire wear
Suspension noise or misalignment
Steering-wheel wobble or vibration

STEERING PARTS

Power Steering
The hydraulic power-steering pump is a constant displacement pump that provides hydraulic pressure and flow for the power-steering gear. The hydraulic power-steering pump is typically belt-driven from the engine.

Signs of Wear:
Fluid leakage
Difficult low-speed steering
Whining noise while turning
Steering-wheel wobble
Pump-housing leakage

Rack-and-Pinion
This steering assembly uses a long steel bar that is meshed with a pinion gear and connected to rods that turn the front wheels. The rack-and-pinion can be hydraulically assisted by a power-steering pump or electrically assisted.

Signs of Wear:
Excessive play in steering wheel
Steering-wheel vibration
Unusual noises while turning the wheel
High-effort steering wheel operation

Idler Arm
The idler arm in your vehicle acts as a pivot point to the steering linkage assembly.

Signs of Wear:
Irregular tire wear, such as feathering or scrubbing

Pitman Arm
On vehicles that utilize a steering gear, the pitman arm connects the steering gear and steering linkage.

Signs of Wear:
“Wandering” and excessive steering with little directional change

Tie-Rod
The tie-rod end connects or ties the steering linkage to the knuckle, allowing for the transfer of motion to the tire and wheel assembly. Tie rods can be categorized as inner or outer depending on the direct connection it makes and its relationship to the steering system.

Signs of Wear:
Rough or stuttered steering
Play in steering wheel
Inner or outer tire-edge wear

BRAKES

Brake Caliper
The brake caliper is a hydraulic clamp that pinches the brake pad onto the brake rotor.

Signs of Wear:
Brake lock-up
Vehicle pulls to the left or right when brakes are applied
Reduced braking force
Spongy brake-pedal feel
Brake-pedal pulsation
Longer stopping distance
Fluid leakage near caliper

Brake Pads
These flat pads comprised of frictional material make contact with the rotor, bringing your vehicle to a stop.

Signs of Wear:
Chirping, grinding, or squealing noise
Difficulty stopping
Low brake-pedal height

Brake Rotors
The brake rotors are rotating discs that help slow or stop the vehicle when the brake pads make contact.

Signs of Wear:
Brake-pedal pulsation
Squealing or grinding noise
Low brake-pedal height
Vehicle pulls to the left or right when brakes are applied

Brake Shoes
Used mostly in rear-braking systems, brake shoes press against the inside of the brake drum to cause friction, slowing or stopping your vehicle.

Signs of Wear:
Low brake-pedal height
Longer stopping distances
Squealing or unusual noises
Brake-pedal pulsation

Brake Hose
The brake hose carries brake fluid from the solid-steel brake lines on your vehicle’s frame to the caliper or wheel cylinder. Flexible brake hoses are necessary to allow the caliper or wheel cylinder to move freely with your vehicle’s suspension.

Signs of Wear:
Spongy brake-pedal feel
Visible hose cracks
Fluid leaks
Damp appearance on hose
Vehicle pulls to the left or right when brakes are applied

BELTS, HOSES, & FILTERS

V-Ribbed Serpentine Belt
This belt transfers power from the crankshaft to the alternator, water pump, air-conditioning compressor, and power-steering pump (if applicable).

Signs of Wear:
Slipping and/or squealing belt
Dimming headlamps while driving
Loss of battery charging

Timing Chain/Belt
Your vehicle’s timing chain/belt synchronizes the engine’s camshaft and crankshaft.

Signs of Wear:
Engine stops
Engine backfires
Irregular engine noise

Air-Conditioning Hose
Refrigerant stored under high pressure is transferred from your vehicle’s evaporator in the engine compartment to the condenser in front of the radiator.

Signs of Wear:
AC inoperative

Heater Hose
The heater hose within your vehicle routes the hot engine coolant to the heater core to heat the cabin.

Signs of Wear:
Coolant leak
Cracking/hardening/brittleness of hose

Radiator Hose
The radiator hose moves coolant from the engine to the radiator to be cooled.

Signs of Wear:
Leaking
Elevated engine temperature
Coolant leak
Cracking/hardening/brittleness of hose
“Check Engine” light illuminates

Engine Air Filters
These filters prevent harmful debris from entering the engine.

Signs of Wear:
Sluggish acceleration
Decreased fuel efficiency

Oil Filter
Your vehicle’s oil filter cleans the engine oil to help reduce wear on the engine’s internal components.

Signs of Wear:
Oil leaks

Automatic Transmission Filter
This filter keeps certain abrasive particles in the transmission fluid from reaching the transmission’s internal components.

Signs of Wear:
Late shifts
Slipping in and out of gear

In-Line Fuel Filter
This filter is designed to trap fuel contaminants before they enter the engine’s fuel-delivery system.

Signs of Wear:
Lack of power
Vehicle will not start
Vehicle only runs in idle or low speeds

Cabin Air Filter
Cabin air filters prevent a majority of airborne particles from entering the cabin.

Signs of Wear:
Decreased climate control (heating and AC) airflow

ADDITIONAL SYMPTOMS

ODORS & STAINS

Antifreeze or coolant leak
Sweet odor, usually accompanied by steam from under the hood.

Axle leaks
Black stains

Burning oil
Thick, heavy odor, sometimes accompanied by smoke from under the hood or from the exhaust.

Coolant streaks
Yellow, green, pink, or orange stains that are lighter and thinner than oil.

Crankcase, oil, power-steering fluid leaks
Brownish stains.

Electric short
Acrid odor, like burnt toast.

Emission
Continuous, heavy sulfur odor, like rotten eggs.

Overheated brakes or clutch
Burning rubber odor.

Overheating
Hot, metallic odor usually accompanied by antifreeze/coolant odor.

Transmission oil leaks
Reddish stains.

Brake fluid and fuel leak
A brake fluid leak is brown in color. A fuel leak is rainbow in color.

SERVICE OFFERS AND REBATES

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SCHEDULE YOUR SERVICE

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