Checking the tightness of pipeline and instrument connections (Audi 100 C4)

Air leak in the internal part of the system (from tank to fuel pump) leads to a disruption in the operation of the fuel supply equipment, and a leak in the part of the system that is under pressure (from the fuel pump to the injectors), causes leakage and excessive fuel consumption. The inlet part of the fuel line is checked for leaks using a special device - a tank.



To do this, connect the fuel line from the fuel tank that drains excess fuel, seal it with a plug, then disconnect the fuel supply line from the tank and connect the hose (1) of the tank (4) to it. Fuel from the tank, filled to 4/5 of its volume, controlled by the fuel gauge tube (2), is supplied to the system under a pressure of 0.3 MPa, which is created by the air pump (3) located in the tank. The appearance of air and fuel bubbles at the joints indicates that they are not tight.

Checking the tightness of the engine air intake tract

Loss of tightness of seals and air ducts leads to abrasive (dust) getting into the engine cylinders, which causes increased wear of the cylinder-piston group and premature engine failure. Air leaks when the engine is running at maximum speed are detected by an indicator.

Indicator for checking the tightness of the air intake tract

To do this, unscrew the screw (2) to the lower edge of the hole (1), then take the indicator with the eye towards you with your left hand, and with your right hand, taking the rubber tube with a fork and tip (3), apply the tip to the places of possible leakage of the air tract. If the liquid level begins to drop, then a gap has been detected. It is necessary to check all possible places of leakage, mark and eliminate them.

After finishing the work, tighten the screw (2) until it stops and put the indicator in the case. Antifreeze, diesel fuel or kerosene are used as liquid.