fuel fill cap is the only venting component on modern day fuel tanks.

If the vent valve is not working, it can cause the tank to have the sides and bottom sucked in. Under normal operation, the evaporative emissions system will allow outside air to enter the tank. When the fuel pump removes fuel from the tank, a vacuum is produced. Often the leading cause of fuel tank contaminates is a missing fuel cap. While plastic fuel tanks do not have the same issues with internal corrosion, it is still possible for dirt and debris to make it into the tank through the filler and neck.

The sock also has a limited capacity due to its small surface area. A conventional inline fuel filter can catch particles as small as 10 microns. Forty microns is the size of a human hair. The typical sock or filter is designed to trap particles that are between 50-100 microns in diameter. If you think the new sock or filter on the full pump will catch all of the bad stuff, you are wrong. There are cleaning options out there ranging from replacement tanks to kits that have the correct solvents that can flush all of the contaminants out of the fuel tank. Your goal should be to restore the inside of the tank to the same state it was when they put fuel in before it drove off the assembly line. Removing all contaminants from the tank is critical before replacing a fuel pump. Most in-tank filters and socks will catch large pieces, but even small pieces of grit can damage the pump. Clean The TankĮven the smallest piece of debris can damage the pumping elements inside the fuel pump. The key to making sure the new pump will not suffer the same fate, is to reset the environment to a like-new condition in the fuel tanks, lines and related electrical systems. In some cases, the endplay in the motor can cause the turbine, rotors or vanes to come in contact with the housing and be damaged.īut, wear and damage to the pumping elements and electric motor are often faults of the environment inside the tanks and at the fuel rail. When this happens, the pump stops turning. When a fuel pump does truly fail, it is typically a case where the brushes on the motor and the bearings that hold the armature in place wear out.

Fuel fill cap is the only venting component on modern day fuel tanks.