6.4. Check of a state and replacement of fuel lines and their nipple connections

See Dropping pressure in a power supply system of petrol engines, Preventions.

Lines of a fuel path of a power supply system are laid between a gasoline tank and a motive compartment. Steel tubes and flexible fuel hoses fasten to the car bottom by means of clips and screw fixture. Every time when the car rises above the ground with any purpose (for example, for survey or replacement of components of system of production of the fulfilled gases), try to take an opportunity and to check a condition of fuel lines and their nipple connections.

Attentively examine all hoses and tubes of a fuel path on existence of cracks, twisting, deformations and other mechanical damages.

At identification of signs of internal pollution or violation of passability the corresponding section of a fuel path needs to be removed and blown compressed air.

Make sure of reliability of delay in all nipple connections of hoses and metal tubes of a fuel path.

Steel tubes

Use only high-strength steel tubes of production of the manufacturers who proved in the automobile market as replaceable sections.

Remember that copper and aluminum tubes are not capable to sustain the vibration loadings arising in use the car.

Do not forget that fuel lines on the models equipped with system of injection have to maintain high internal pressure.

Often in company shops of automobile accessories it is possible to get the sections of metal tubes equipped with carving nipple nozzles. During the easing and delay in nipple connections use two wrenches to avoid a provorachivaniye of a reciprocal part of the socket. Without fail check a condition of the nipple connections of sealing rings used for sealing. At once replace the worn-out or mechanically damaged rings. Try to use only company details as replaceable components.

Flexible hoses

When replacing fuel hoses use only company components calculated on high internal pressure!

Flexible fuel hoses have to be laid not closer than in 10 cm from components of system of production of the fulfilled gases and are not closer than in 25 cm from the catalytic converter. You watch that fuel lines did not adjoin to body elements and components of a suspension bracket. The minimum admissible size of a gap makes 6.3 mm.



  1. Dump pressure in a power supply system (see System of the consecutive distributed injection (SFI)).
  2. Release the section of a fuel path which is subject to dismantle from intermediate clamps of fastening it to the car bottom.

In most cases flexible hoses fasten to metal lines by means of collars of spring type. For an otpuskaniye of a collar squeeze it flat-nose pliers and shift up a hose. The collar deformed at an otpuskaniye is not subject to reuse and has to be replaced. Track that at connection the hose was tense on a tube at least on 2.5 cm, establish by the correct image a fixing collar.

In some nipple knots sockets of bystry joining are used — for an otpuskaniye of such socket it is necessary to squeeze his lock uvulas and to pull the connected lines in different directions.


  1. Squeeze lock uvulas …
  1. … release a clamp …
  1. … and a rasstykuyta I will corrode.

Needlessly do not pick up the socket case from a nipple part of the metal phone as it leads to easing of the holding effort developed by it!

Nipple sockets of bystry joining are not subject to recovery repair and in case of their exit out of operation the corresponding section of the line has to be replaced assembled.

Installation is made upside-down. On sockets of bystry joining track a zashchelkivaniye of both lock uvulas in reception flutes.


In case of damage of the metal or flexible fuel line the failed section should be replaced only company the corresponding standard size.