2. Disconnect from the gravitational valve 19 hose to an adsorber 21.
3. Unbend spring clips and take out upwards the valve 19 of a bulk pipe of a fuel tank.
4. Blow the valve air. In vertical position the valve should be opened, at an inclination at an angle 45 should be closed. If it does not occur, means, the valve is faulty also it it is necessary to replace.