What should DEF air pressure be?
Detroit Diesel DEF Pump Module Air Bladder You then need to regulate your shop air pressure to 55 PSI and re-inflate the air bladder to 40-46 PSI through the Schrader valve as shown in the image to the right. At this point, you would go back to your diagnostic tool and run the “DEF Quantity Test” next.
What does the DEF metering valve do?
The metering valve holds back fluid to the front brakes until enough pressure is created to overcome the return springs inside the rear drums. It is also known as a “metering block.” The metering valve is plumbed into the system immediately after the Master Cylinder.
Where is the DEF pressure sensor?
A DEF quality sensor is mounted on the side of the DEF tank. This sensor detects the Urea concentration in the DEF to confirm it is acceptable for effective dosing (approximately 32.5% Urea).
Where is the DEF metering valve located?
The DEF metering unit is mounted on the back side of the exhaust emissions box. The arrow indicates the location of the filter on the DEF pump.
How do you test a pump definition?
Field Testing
- Visually inspect DEF for color and clarity.
- Do a “smell test”.
- Inspect exhaust piping and DEF injectors for presence of crystallization.
- Use a handheld DEF refractometer to measure the concentration specifications of the fluid to ensure 32.5% of the fluid is urea.
What is a DEF dosing unit?
Dosing Unit. The dosing unit, or injector, is a robust component that delivers an atomized urea and air mixture upstream of the SCR catalyst. The design allows injection in the center of the exhaust gas flow, which minimizes the risk of deposits and improves reliability.
What is a height sensing proportioning valve?
Height-Sensing Proportioning Valves Instead of restricting pressure, this valve adds more hydraulic pressure to the rear brakes to generate greater braking force than the front. As its name suggests, the height-sensing proportioning valve works by adjusting rear brake pressure depending on the vehicle’s height.
What causes DEF pump failure?
Dirt / Metal Contamination: Contaminated DEF can cause abrasion of the DEF pump. Other Fluids: Contamination of the DEF tank from other fluids such as diesel fuel, coolant, or engine oil being added can cause damage to the SCR system and engine shutdown.
What is a Qls sensor?
The integrated Urea Quality Sensor (UQS) is a sensor that directly and simultaneously measures the chemical properties of aqueous urea solution. The UQS is an important tool for meeting regulated OBD compliance to confirm urea presence and concentration and security signal communication.
What does a DEF system do?
Diesel Exhaust Fluid (DEF) is a solution of urea and water that’s injected into the exhaust stream of diesel vehicles to turn NOx gases (harmful emissions) into nitrogen and water. This system is called a Selective Catalytic Reduction (SCR) implemented by vehicle manufacturers to meet EPA emissions standards in 2010.
How much does a DEF pump cost?
The average price of U.S. diesel exhaust fluid rose 4 cents from September and October, to an average of $2.80 per gallon, reports DEF Tracker. This is the second highest average pump price in the last 12 months, behind June at $2.88 per gallon.
What does it mean when air pressure is high or low?
Areas where the air is warmed often have lower pressure because the warm air rises. These areas are called low pressure systems. Places where the air pressure is high are called high pressure systems. A low pressure system has lower pressure at its center than the areas around it.
How is the pressure of the air around you measured?
Barometer. The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exert ed on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer.
What is the pressure at the bottom of the atmosphere?
We live at the bottom of the atmosphere, and the weight of all the air above us is called air pressure. A tower of air that is 1-inch square and goes from the bottom of the atmosphere is 14.7 pounds. That means air exerts 14.7 pounds per square inch (psi) of pressure at the Earth’s surface. High in the atmosphere, air pressure decreases.
How is atmospheric pressure measured in a barometer?
Barometer. That pressure is called atmospheric pressure, or air pressure. It is the force exert ed on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer. In a barometer, a column of mercury in a glass tube rises or falls as the weight of the atmosphere changes.
