How Leak Detection Pumps Work: A Guide for Students in Auto Repair Programs

What would happen if leaks in coolant, oil and other vehicle fluids constantly went unnoticed? At the very least, drivers would be due for some costly repairs. However, with the invention of leak detection pumps a few decades ago, vehicle manufacturers have developed a way to detect when a leak is present within a vehicle. The leak detection pump identifies leaks when they’re present within a vehicle’s systems, activating the Check Engine light in order to alert drivers of a problem. Thanks to the fact that every modern vehicle is equipped with a leak detection pump (LDP), today’s drivers know when to take their vehicle to a repair shop in the case of a leak. If you’re entering a career in the auto repair industry, discover more about what a leak detection pump does, and how it works in the blog below. 

Purpose of a Leak Detection Pump Explained for Professionals in an Auto Mechanic Career

Leak detection pumps are important mechanisms within a vehicle. These components work to identify leaks within a vehicle’s evaporative emissions control (EVAP) system. When a vehicle’s engine emits vaporized gas as a result of combustion, the EVAP system is responsible for taking in and storing this gas. The leak detection pump works to pump pressurized air into the EVAP system, which forces the system to diagnose any leaks that may be present. The consistent checking for leaks that the LDP facilitates allows leaks to be found before they create a more serious issue for a vehicle. Once a vehicle is brought in for an identified leak, a professional in an auto repair career will use the diagnosis obtained to conduct necessary assessments and repairs. 

Leak detection pumps identify leaks within a vehicle’s EVAP system

How Leak Detection Pumps Operate

Leak detection pumps operate by pumping pressurized air into the EVAP system, where the air is used to allow the system to conduct a diagnostic assessment for leaks. A leak detection pump consists of a few main components, including a diaphragm, a vent valve, a vacuum solenoid, a sensor and multiple different one-way valves. The vacuum solenoid works to support the pump’s movement of the diaphragm by controlling the rhythm of its up and down movement. This movement creates the pressure utilized by the EVAP system. Once the maximum amount of pressure is reached, the motion of the diaphragm ceases and the vent valve closes. The EVAP system is then sealed, after which the engine control unit (ECU) can begin the process of leak diagnosis. If the ECU detects any abnormal readings, the Check Engine Light will turn on, signaling to the driver that their vehicle needs to be serviced by an auto mechanic career professional.

If a leak is detected by a LDP, the vehicle will need to be serviced by a professional mechanic

What to Do When Leaks Are Detected

When the ECU detects a potential leak within the EVAP system, auto repair technicians must address the situation by performing a more thorough assessment of a vehicle. If you’re entering a career in auto repair, it will be important to check the levels of oil, coolant, and other fluids within a vehicle, searching for any abnormalities. Once the source of a leak has been identified, the parts in question will need to be repaired or replaced. By addressing the source of a leak when a LDP identifies it, you can prevent vehicles from sustaining further damage as a result of the leaking fluid.

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