2.9. Check and replacement of hoses

Replacement of hoses of the air conditioning system needs to be made at the service station having the equipment for depressurization of system.

High temperature serves as the reason of deterioration in properties of rubber and plastic hoses in a motor compartment. Periodic survey has to help to reveal cracks, the weakened fastenings, local hardenings and leaks.

Fig. 2.11. Damages of a hose of a radiator: and – the burned areas; b – the softened places; with – hardening; d – the areas of a hose inflated or impregnated with oil

Check hoses for lack of the burned areas which can lead to expensive repair of the engine (fig. 2.11).
"Softness" of a hose indicates internal wear which can pollute the cooling system and litter a radiator.
The rigid hose can collapse at any time. The inhaling of collars of fastening of a rigid hose to a branch pipe will not provide tightness of connection and will not stop a leak.
The inflated hose or the ends of a hose impregnated with oil indicate possible leakage in the lubrication system.

Vacuum hoses
Leak in a vacuum hose means that air is sucked in in a hose (but does not leave a hose), and it does leak very difficult for detection.
The method of detection consists in using an old vacuum hose as some kind of stethoscope. You keep one end of a hose close to an ear (but not in fish soup), and use other end for inspection of area around alleged leak. When the end of a hose directly is over the place of leak, through a hose the hissing sound will be clearly heard. It is necessary to avoid contact with hot and moving details as an inspection should be carried out at the working engine.

At a research of a vacuum hose a stethoscope be attentive – do not allow contact of your body or hoses with mobile elements of the engine, such as driving belts, fan, etc.

Fuel hoses
The power supply system fuel is under pressure therefore before a detachment of pipelines it is necessary to reduce pressure in system.

Gasoline is extremely flammable therefore during the work with power supply system elements as fuel use of fire, is forbidden by the sparking devices opened by fire-dangerous light devices, smoking. It is necessary to avoid emergence of sparking during the work with wires and electric devices.
As gasoline is cancerogenic substance, it is necessary to exclude its hit on a body and a paint and varnish covering of the car. Otherwise it is necessary to wash out immediately this place water with soap.

Check all rubber fuel hoses for lack of wear and attritions. Especially carefully check places of an excess of hoses before clips in places of accession of hoses to the fuel pump, the fuel filter and the carburetor.
For replacement it is necessary to use quality fuel-supply lines which are identified by the inscription "Ruroelastomer" on a hose. It is impossible to use for replacement of a fuel-supply line a vacuum hose, the cleared plastic tube or a water hose at all.
Usually for fastening of fuel-supply lines on branch pipes spring clips which lose the elasticity over time are used, and also can "otpruzhinit" at their removal. Therefore every time when replacing a hose is recommended to replace all spring clips with screw.

Metal pipelines
Pieces of metal tubes are often used as a fuel-supply line between the fuel pump and the carburetor. Make sure that the tube is not bent and is not goffered and that there are no splits in the field of bends.
For replacement of a piece of a metal fuel-supply line it is necessary to use only a steel seamless tube as copper and aluminum tubes do not maintain vibration during the operation of the engine.
Check metal tubes of the brake system in places of their accessions to the main brake cylinder and the regulator of pressure (if it is used) upon lack of cracks on tubes or weakening of connections. Any traces of leak of brake fluid mean need of immediate and full survey of the brake system.