Audi A4 B6 - the Repair manual and operation

1.8. Automobile chemicals, oils and lubricants

The cleaner for brake systems is applied to removal of traces of lubricant and brake fluid from surfaces a component of the brake system where absolute purity is a paramount condition of efficiency of functioning. The cleaner does not leave any marks and in many cases eliminates the squeal of brake mechanisms caused by pollution their component.

The cleaner for electric a component promotes elimination of oxide films, traces of corrosion and a deposit from contact surfaces without conductivity violation. Also it can be used for cleaning of spark plugs, jets, regulators of tension and other knots where full cleaning of oil and fat is desirable.

Moisture absorbers serve for removal of water and moisture from so electric surfaces a component as the generator, tension regulator, a box of safety locks, electric sockets, etc. of Vlagopoglotiteli usually are not conducting, not causing corrosion and not flammable.

Degreasers represent superstrong solvents and serve for removal of traces of lubricant from the external surfaces of the engine and a chassis component. Are issued in the form of aerosols or are put with a brush or a brush and, depending on type, wash off or, or solvent.

The greasing liquids

Motive oils represent specially developed structures for lubricant internal an engine component. Usually contain different wide range of the additives serving for prevention of foaming and corrosion. Motive oils are produced various degree of viscosity - from 5 to 80. Need of use of oil of this or that grade usually is defined by climatic conditions and requirements of the concrete engine. Liquid (lungs) oils are usually applied in a frigid climate and at insignificant loads of the engine. Heavy (viscous) oils are used in hot conditions and at the raised loads of the engine. All-weather oils possess characteristics of both light, and heavy oils and usually have designations from 5W-20 to 20W-50.

Qualities of motive oils

All-weather oils are rather inexpensive oils with the following qualities:

– year-round use in zones of a temperate climate;

– the excellent washing properties;

– the good greasing ability at all temperatures and loadings of the engine;

– high stability of initial properties for a long time.

All-weather oils with the improved antifrictional qualities have, besides, additional advantages:

– honor year-round use at all possible temperatures of external air;

– small losses of engine capacity on friction;

– simplification of cold start of the engine – even at very low temperatures.

Seasonal oils owing to specific viscous and temperature properties inherent in them usually cannot be used all the year round. Therefore these oils should be applied only in extreme climatic zones.

When using all-weather oils of the class SAE 5W-30, it is necessary to avoid long operation of the engine with high frequency of rotation and constant big load of the engine. These restrictions are not valid for all-weather oils with the improved antifrictional qualities.

Additives to motive oils

It is not necessary to add any additives reducing losses on friction to motive oils.

Follow the rule: always to use the high-quality oil of one brand corresponding to the engine (on classification) and not to risk to mix it with same synthetic (or semi-synthetic) oil. The engine will thank for it reliable work. Do not buy oil privately as it is easy to forge packing.

Gearbox oil is developed for application in differentials, transmissions, and other knots where resistance to influence of high temperatures is required.

Lubricant for a component of the chassis and bearings of wheels represents the dense lubricant applied in the knots subject to the raised loadings and friction, such as bearings of wheels, spherical support of a suspension bracket, tips of steering drafts and cardan hinges.

High-temperature lubricant for bearings of wheels is capable to resist to influence of the high temperatures arising in bearings of wheels of the cars equipped with disk brake mechanisms. Usually contains the molybdenum disulfide which is the greasing substance of dry type.

White lubricant (tsiaty) represents the dense lubricant applied on the metal surfaces contacting among themselves in places where there are problems with the increased moistening. Remains soft both at low, and at high temperatures, it is not washed away and not diluted by water.

Assembly lubricant represents special lubricant, for application in the conditions of high pressures, usually contains molybdenum and is used for greasing of the knots subject to the raised loadings (such as radical and conrod bearings and working ledges of cams) before the first start of the engine after completion of capital repairs.

Silicone lubricants are applied to protection rubber, plastic, vinyl and nylon a component.

Graphite lubricants serve for application where oil cannot be used in a type of problems with pollution (for example, in locks). Dry graphite perfectly greases metal details, preventing influence on them of moisture, acids and other aggressive pollution. Lubricant is electrowire and does not break contact in such knots as, for example, the ignition lock.

The Molibdensoderzhashchy getting structures are applied to simplification of an otdavaniye of the "stuck" fixture, and also to greasing of fixture in order to avoid its corrosion in the future.

Heat-conducting lubricant is not electrowire and serves for installation of electronic blocks of ignition from which intensive heat removal is required.

Sealants

RTV sealant is the most widely applied pro-masonry sealant. It is made on the basis of silicon, stiffens on air, provides sealing, gluing, is waterproof, fills defects of surfaces, remains elastic, does not contract and does not sit down, it acts rather easily and applied in addition practically to all laying on knots where temperatures do not exceed average values.

Anaerobic sealant unlike RTV sealant can be applied not only in addition to laying, but also to formation of those. Remains elastic, it is steady against influence of solvents and well fills roughnesses of surfaces. The main difference from RTV sealant consists in hardening conditions. If RTV sealant begins to stiffen after hit on air, then anaerobic sealant rises only in lack of air. It means that hardening of such sealant happens only after assembly a component and their dense pressing to each other.

Sealant to pipes and threaded connections is applied to sealing of nipple connections of hydraulic, pneumatic and vacuum lines. It is usually made on the basis of a teflon compound and delivered in the form of the aerosols put like paint of liquids or in the form of the film (FUM).

Chemicals

The anti-taking compound serves for the prevention of "prikipaniye", corrosion, jamming and a cold privarivaniye of fixture. The high-temperature anti-taking sealants usually are made on the basis of cupriferous or graphite lubricants and used in fixture of system of release and a final collector.

The anaerobic taking compounds serve for prevention of a spontaneous otdavaniye of fixture as a result of vibrations and stiffen only after installation in lack of contact with air. The taking compounds of average power are applied to fixing of small fixture (nuts, bolts, screws) which are subject to a regular otdavaniye further. High-power compounds are usually used for blocking of large fixture which otdavaniye is not made on a regular basis.

Additives to oil serve for change of chemical properties of oil without change of its viscosity for the purpose of decrease in internal friction in the engine. It is necessary to notice that most the firms manufacturers producing engine oils is prevented against use of any additives to them.

Additives to fuel perform several functions, depending on the chemical composition at once. Usually contain the solvents promoting a conclusion of slags and removal of a deposit from internal surfaces and a component of system of injection of fuel and an inlet path. Besides, use of such additives promotes removal of the coal deposits which are formed on walls of combustion chambers. The substances serving a component of the top part of a head of cylinders (the valvate mechanism, piston rings) for greasing are a part of some additives, others promote removal of condensate from walls of the fuel tank.

Others

Brake fluid - represents specially developed structure capable to resist to influence of the high temperatures and pressure arising in the brake system. It is not necessary to allow contact of brake fluid with the painted surfaces of the car and open parts of the body. Brake fluid is poisonous. It is necessary to keep brake fluid in hermetically closed container in order to avoid hit of moisture in it (liquid is very hygroscopic) and dirt.

During operation of the car brake fluid takes away a certain amount of water from air. Too high content of water in brake fluid can cause, eventually, corrosion of details of the working brake system. Besides, at the same time temperature of boiling of brake fluid significantly goes down.

Therefore it is necessary to change time in two years brake fluid!

At very old brake fluid it is possible, at big load of the working brake system, emergence of vials of steam in system. It negatively influences overall performance of the working brake system and, thereby, traffic safety.

It is necessary to apply only the recommended brake fluid.

Glue for fastening of sealing strips of body apertures as it is clear from its name, serves for fastening of sealing strips of apertures of doors, windows and covers of luggage compartments. It can be applied to fixing of elements of internal finishing.

Anticorrosive coverings for the bottom of the car are represented by the gudronoobrazny structure made on an oil basis and serves for a sheeting of metal surfaces, preventing their corrosion. Besides, performs function of sound insulation of salon.

Wax and polish are applied to protection of the painted surfaces against influences of the environment. Uses of various type of vosk and polishes can demand various type of paint. The abrasive or chemical additives serving for removal of an external layer of oxides (tarnishing) from the painted surfaces of old cars are a part of some polishes. Recently are widely presented at the market different polishes which are not containing wax which part the set of chemical additives, such as polymers or substances on a silicon basis is. Such polishes are put and keep longer than usual (wax) usually easier.