Renault Megane, Scenic

Since 1996 of release

Repair and car operation

Technology of service, the tool and the workplace equipment

Technology of service

There are some techniques of performance of procedures of maintenance service and car repairs on which the reader will find references in the text of the given management. Following by it will make work of the house mechanic of more effective, will allow to organise in the best way and qualitatively to execute various technical procedures and is pledge of careful and full performance of all works.

Fixture

As fixture are called nuts, bolts, hairpins and the screws serving for connection among themselves of two or more details. At work with fixture it is necessary to remember some things constantly. Practically in any fixture this or that kind контрящих and stopping adaptations is applied. It can be lock washers, counternuts, lock tags or fixing компаунд for carvings. All used carving fixture should be absolutely pure and direct, with not broken carving and not rounded corners шестигранных heads which the wrench is put on. It is necessary to take for a rule obligatory replacement of the damaged nuts and bolts on new. Special самоконтрящиеся nuts with nylon or fiber inserts are not subject to a reuse, as at отдавании lose the контрящие properties and at assemblage always should be replaced with the new.
Prirzhavevshie bolts and nuts for simplification of unscrewing and in order to avoid damage before отдаванием should be processed special getting structure. Many mechanics prefer to use for this purpose turpentine which it is convenient to put from the special small canister with a long nouse. After wetting of the "become attached" fixture by getting structure before starting to it отдаванию, it is necessary to give to structure within several minutes properly to impregnate the oxidised contact layer. Strongly rusted fixture can be cut down a chisel, is cut ножовкой or removed by means of special гайколома.
At cutting of a head of a bolt or обламывании hairpins on assemblage, the rest of a carving part can be drilled or taken by means of the special tool. The majority of repair trucks can undertake performance of this, also as well as others (for example, restoration of the broken carving in carving apertures), repair procedures.
Flat and lock washers at assemblage should be established always into place in the same order and the same way, as earlier. The damaged washers always replace with the new. Between a lock washer and a soft metal surface (for example, aluminium), thin sheet metal or plastic always it is necessary to establish flat washers.

The sizes of fixture

For many reasons manufacturers of cars all apply metric fixture more widely and more widely. However, it is important to know a difference between used sometimes standard (named also American, or standard SAE) and more universal in system of measures metric fixture as, despite external similarity, they are not interchangeable.
All bolts, both standard, and metric are classified on diameter, a step of a carving and length. For example, the standard bolt 1/2 — 13 * 1 has an inch floor in diameter, 13 coils of a carving on one inch and length of 1 inch. Metric bolt М12 — 1.75 * 25 has diameter of 12 mm, a step of a carving of 1.75 mm (distance between the next coils) and length of 25 mm. Both bolts are outwardly almost identical, however are not interchangeable.
In addition to the listed signs both metric, and standard bolts can be identified by head survey. To begin with, the distance between лысками heads of a metric bolt is measured in mm, whereas at standard — in inches (the same is fair and for nuts). As consequence, the standard wrench is not necessary for use with metric fixture, and on the contrary. Besides, on heads большей parts of standard bolts usually are available the radial notches defining the maximum admissible effort of a tightening of a bolt (durability degree). The more quantity of notches, the above admissible effort (on cars bolts with degree of durability from 0 to 5 are usually applied). The class of durability of metric bolts is defined by a digital code. Code figures are usually cast, as well as for standard, on a bolt head (on cars bolts of classes of durability 8.8, 9.8, and 10.9 are usually applied).
Also on labels of a class of durability standard nuts can be distinguished from the metric. Dot labels are applied to identification of durability of standard nuts, проштамповываемые on one of face surfaces of a nut while marks of metric nuts are made with the help besides figures. Than quantity of points, or the above value of a digital code, the above admissible effort of a tightening of a nut more.
End faces of metric hairpins also are marked according to a class of their durability. Large hairpins are marked by a digital code whereas marks are put on smaller in the form of a geometrical figure.
It is necessary to notice that the considerable part of fixture, in particular a class of durability from 0 to 2, is not marked at all. In this case unique way of difference of standard fixture from metric is measurement of a step of a carving, or сравнивание carvings with unequivocally identified.
Standard fixture often name also, contrary to metric, fixture of standard SAE, however, it is necessary to remember that under classification SAE only small fixture gets. The large fixture with not metric carving is fixture of the American standard (USS).
As the fixture of the same geometrical size (both standard, and metric) can have various classes of durability, at replacement by the car of bolts, nuts and hairpins it is necessary to pay attention to conformity of a class of durability of established new fixture to a class of durability of the old.

Marks of a class of durability of bolts

Above — standard/SAE/USS, Below — metric

Marks of a class of durability standard шестигранных nuts

Class identification	Durability class
	Shestigrannaja nut Class of durability 5 Three points
	Shestigrannaja nut Class of durability 8 Six points

Marks of a class of durability metric шестигранных nuts

Class identification	Durability class
	Shestigrannaja nut Class of durability 9 Arabian 9
	Shestigrannaja nut Class of durability 10 Arabian 10

Marks of a class of durability of metric hairpins

The sizes/marks of a class of durability standard (SAE and USS) bolts

G – Marks of a class of durability L – Length (in inches) T – a carving Step (quantity of coils on inch) D – Nominal diameter (вдюймах)

The sizes/marks of a class of durability of metric bolts

P – a durability Class L – Length (in mm) T – a carving Step (distance between the next coils in mm) D – Nominal diameter (in mm)

Procedure and order of a tightening of carving connections

The tightening большей should be made parts of carving connections with the efforts defined by requirements of Specifications, resulted in the beginning of each Chapter of the given Management (it is necessary to understand as effort of a tightening of fixture put to it at a tightening a twisting moment). More low the effort of a tightening will be called also as the moment of an inhaling of fixture. The tightening with excessive effort can lead to infringement of integrity of fixture whereas недотягивание it conducts to unreliability of connection of interfaced components. Bolts, screws and hairpins, depending on a material of which they are made also diameter of a carving part, usually have strictly certain admissible moments of an inhaling, many of which as already it was mentioned above, are resulted in Specifications in the beginning of each Chapter. Strictly adhere to the resulted recommendations about the moments of an inhaling of fixture applied on the car. For a tightening of the fixture which has been not mentioned in Specifications, it is necessary to use the map of the admissible moments of rotation resulted more low. The values resulted in the table are focused on fixture of classes of durability 2 and 3 (more high-class fixture supposes a tightening with the big effort), besides, it is meant that the tightening dry (with not greased carving) fixture in steel or cast (not aluminium) a detail is made.

The sizes of metric carvings

M – 6	9 – 12 Nanometers
M – 8	19 – 28 Nanometers
M – 10	38 – 54 Nanometers
M – 12	68 – 96 Nanometers
M – 14	109 – 154 Nanometers

The sizes of trumpet carvings

1/8	7 – 10 Nanometers
1/4	17 – 24 Nanometers
3/8	30 – 44 Nanometers
1/2	34 – 47 Nanometers

The sizes of carvings of the American standard

1/4 – 20	9 – 12 Nanometers
5/16 – 18	17 – 24 Nanometers
5/16 – 24	19 – 27 Nanometers
3/8 – 16	30 – 43 Nanometers
3/8 – 24	37 – 51 Nanometers
7/16 – 24	55 – 74 Nanometers
7/16 – 20	55 – 81 Nanometers
1/2 – 13	75 – 108 Nanometers

Any fixture located on a perimetre detail (such as bolts of a head of cylinders, the pallet картера and various covers), in order to avoid detail deformation should be given and be tightened in strictly certain order. The order of a tightening and отдавания such fixture is resulted in corresponding Heads of the Management. If the special order is not stipulated, in order to avoid a component curvature it is necessary to adhere described below procedure. At the first stage all bolts or nuts should be tightened by hand. Further, each of them should be by turns held on on one complete revolution, and transition of odes of one bolt/nut to another should be carried out in a diagonal order (cross-wise). Further, having returned to the first bolt/nut, it is necessary to repeat procedure in the same order, tightening fixture for a half-turn. Continue to operate in the same manner, tightening each bolt/nut this time already on a turn quarter for one approach until all of them will not appear tightened with demanded effort. At отдавании fixture as it is necessary to adhere to the described procedure, but operating upside-down.

Dismantling of components

Dismantling of all components should be carried out in such manner that at assemblage each detail could be established on the former place and correct image. Remember prominent features of appearance, in case of need make landing marks of the details which installation can be into place made in the ambiguous image (to such elements the persistent washer equipped with a flute on a shaft) concerns, for example. The arrangement of the removed details on a pure working surface in that order in what their removal was made will be good idea. Useful there will be also a drawing up of the elementary schematic sketches or step-by-step photographing of a component subject to dismantle.
At fixture removal try to make marks of its initial position on assemblage. Often, immediate installation of fixture and washers on a former place after removal of a corresponding detail allows to avoid mess at assemblage. In the absence of such possibility, all fixture should be put in specially prepared for this purpose broken into sections and accordingly marked box, or it is simple on the separate marked boxes. Such line of action appears especially useful at work with the components consisting of set of fine details, such as the carburettor, the generator, клапанный the mechanism, the panel of devices or elements of a decorative upholstery of salon.
At a detachment of electric contacts and sockets it is necessary to pay attention to marks of wires or plaits with the help изоляционной tapes with the digital on it digital or alphabetic code.

Prokladochnye surfaces

On all cars of a lining are applied to hermetic sealing of a place of a joint of interfaced surfaces of two or more details and serve for prevention of leaks of oils and liquids and maintenance in elevated pressure or depression assemblage.
Often such linings before installation become covered liquid or pastelike sealing компаундом. Often under the influence of time, temperatures or pressure occurs so strong "прикипание" to each other interfaced surfaces that division of details becomes an exigeant problem. With many cases to dismantle of such assemblages helps обстукивание them outside on perimetre of a place of a joint a hammer with soft the brisk. It is possible to take advantage for this purpose as well of a usual hammer, putting blows through the wooden or plastic prorate. It is not necessary to make обстукивание cast cases and fragile components. Whether at occurrence of such difficulties always first of all check weigh fixture it is removed.
Avoid application for division of details a screw-driver or mount, entering them between interfaced surfaces as sealing surfaces can be thus easily damaged that further can be at the bottom of occurrence of leaks. If подрычаживания it is impossible to avoid "the become attached" elements of assemblage, use for this purpose the handle from old сметки, but remember thus that after all the formed chips should be carefully removed from interfaced surfaces and from within assemblage.
After division of details their interfaced surfaces should be smoothed carefully out with соскабливанием traces of a material of an old lining. The hardened fragments of an old lining can be preliminary softened by means of the converter of a rust or a special chemical compound then are removed from an interfaced surface by a scraper. As a scraper the piece of a copper tube with the flattened out and pointed end in this case can be used. Use for this purpose of a copper tube is recommended, as copper usually is softer than materials applied in the car that reduces risk of damage of an interfaced surface. Some linings easily can be removed by means of a copper brush, however, is not dependent on the applied method, interfaced surfaces should become absolutely pure and smooth. If for any reason the interfaced surface has appeared scratched, before assemblage of components fill a scratch прокладочным with hermetic. In most cases it is necessary to use not stiffening (or semistiffening) hermetic.

Councils about removal of hoses

If your car is equipped by air central air, at all do not disconnect from conditioner components any hoses until the system will not be discharged in representation branch of the company or the expert in central airs of air of a workshop of car-care centre

Measures of precautions which should be observed at removal of hoses, are very close to that at removal of linings. Avoid damage of surfaces of unions and branch pipes on which hoses as it can be at the bottom of occurrence of leaks put on. In a special measure it concerns procedure of removal of hoses of a radiator. Owing to various chemical reactions occurs "прикипание" rubbers of hoses to interfaced surfaces of unions and branch pipes. For hose removal first of all ослабьте a collar of its fastening on the union. Then nippers with the sli