Service technology, tools and equipment of the workplace

Service Technology

There are several methods for performing vehicle maintenance and repair procedures, which the reader can find references in the text of this manual. Following them will make the work more efficient, will allow you to organize the workplace in the best possible way and perform various technical procedures with high quality.

Fasteners

Fasteners are nuts, bolts, studs and screws used to connect two or more parts. There are a few things to keep in mind when working with fasteners. In almost any fastener, one or another type of locking and fixing devices is used. These can be lock washers, locknuts, lock flags, or thread locking compound. All threaded fasteners used must be absolutely clean and even, with intact threads and not rounded corners of the hex heads on which the wrench is put on. It should be a rule to replace damaged nuts and bolts with new ones. Special self-locking nuts with nylon or fiber inserts cannot be reused, as they lose their locking properties when released.

Rusted bolts and nuts should be treated with a special penetrating compound to facilitate their release and avoid damage. Many mechanics prefer to use turpentine for this purpose, which is conveniently applied from a special small canister with a long spout. After wetting «stuck» fasteners with a penetrating composition, before proceeding with its release, the composition should be allowed to soak the oxidized contact layer for several minutes. Heavily rusted fasteners can be cut down with a chisel, sawed off with a hacksaw or removed with a special wrench.


Threaded connections that are subject to large temperature differences (e.g. EGR valve, lambda probe, exhaust manifold), have a tendency to weld, making it difficult to dismantle at the next service. To ease the release of these fasteners, lubricate them with Molycote 1000 30 20 971 or Never Seize before tightening.

When cutting off the bolt head or breaking off the stud on the assembly, the rest of the threaded part can be drilled out or removed using a special tool. Most locksmiths and auto repair shops can handle this, as well as others (e.g. repairing stripped threads in threaded holes), repair procedures.

Flat washers and lock washers should always be reinstalled in the same order and in the same way as before when reassembling. Always replace damaged washers with new ones. Between lock washer and soft metal surface (e.g. aluminum), thin sheet metal or plastic, flat washers should always be installed.

Fastener dimensions

For many reasons, automotive manufacturers are increasingly adopting metric fasteners. However, it is important to know the difference between the sometimes used SAE fasteners (also called American) and more universal in the system of measures with metric fasteners, since, despite the external similarity, they are not interchangeable.

All bolts, whether SAE or metric, are classified by diameter, thread pitch, and length. For example, a SAE 1/2-13x1 bolt is half an inch in diameter, 13 threads per inch, and 1 inch long. The M12-1.75x25 metric bolt has a diameter of 12mm, a thread pitch of 1.75mm and a length of 25mm. Both bolts are externally almost identical, but are not interchangeable.


In addition to the features listed, bolts can be identified by looking at their heads. The distance between the head flats of a metric bolt is measured in mm, while for an SAE standard bolt it is measured in inches (the same is true for nuts). As a consequence, an SAE wrench is not suitable for use with metric fasteners, and vice versa. In addition, the heads of most SAE bolts usually have radial notches that determine the maximum allowable tightening torque of the bolt (degree of strength). The more notches, the higher the allowable force (on cars, bolts with a degree of strength from 0 to 5 are usually used).

SAE and USS Bolt Dimensions and Markings

Dimensions and marking of the property class of metric bolts

The strength class of metric bolts is determined by a numerical code that is usually cast on the head of the bolt.

Bolt grade marking (top - SAE and USS, bottom - metric)

Also, according to the marks of the strength class, the nuts of the SAE standard can be distinguished from the metric ones. To identify the strength of SAE nuts, dot marks are used, stamped on one of the end surfaces of the nut, while metric nuts are marked again using numbers. The greater the number of points, or the higher the value of the digital code, the higher the allowable tightening torque of the nut.

Strength class marking for standard SAE and USS hex nuts

Three points: Strength class 5

Six points: Strength class 8

Property class marking for metric hex nuts

Arabic 9: Strength class 9

Arabic 10: Strength class 10

The ends of metric studs are also marked according to their strength class. Large studs are marked with a digital code, while smaller ones are marked in the form of a geometric figure.

Strength class marking for metric studs

It should be noted that a significant part of the fasteners, especially the strength class from 0 to 2, is not marked at all. In this case, the only way to tell SAE standard fasteners from metric fasteners is to measure the thread pitch, or compare the thread with a reference.

Since fasteners of the same geometric size can have different strength classes, when replacing bolts, nuts and studs on a car, attention should be paid to the compliance of the strength class of the new fastener being installed with the strength class of the old one.

Procedure and procedure for tightening threaded connections

Most threaded connections should be tightened to the torque specified in the Specifications at the beginning of each chapter in this manual (fastener tightening force is understood as the torque applied to it when tightening). Over-tightening can damage the integrity of the fastener, while under-tightening can lead to insecure connections between mating components. Bolts, screws and studs, depending on their material and diameter of the threaded part, usually have strictly defined permissible tightening forces, many of which, as mentioned above, are given in the Specifications at the beginning of each chapter. For tightening fasteners not mentioned in the Specifications, use the torque chart below. The values given in the table are based on fasteners of strength classes 2 and 3 (Higher grade fasteners allow for more tightening), in addition, it is understood that the tightening of the dry (with unlubricated thread) fasteners in steel or cast (not aluminum) detail.

Tightening torques for metric threads

M6	9 - 12 Nm
M8	19 - 28 Nm
M10	38 - 54 Nm
M12	68 - 96 Nm
M14	109 - 154 Nm

Tightening torques for pipe threads

1/8	7 - 10 Nm
1/4	17 - 24 Nm
3/8	30 - 44 Nm
1/2	34 - 47 Nm

Tightening torques for SAE and USS threads

1/8	7 - 10 Nm
1/4	17 - 24 Nm
3/8	30 - 44 Nm
1/2	34 - 47 Nm

Fasteners located around the perimeter of any part (such as cylinder head bolts, oil pan and various covers), in order to avoid deformation, the parts should be given and tightened in a strictly defined order, described in the relevant chapters of the Manual. If this order is not specified, then the following procedure should be followed to avoid distortion of the component. At the first stage, tighten all bolts or nuts by hand. Then tighten each fastener in turn one more full turn, and the transition from one bolt / nut to another should be done in a diagonal order (criss-cross). Then, returning to the first bolt / nut, you should repeat the procedure in the same order, tightening the fasteners another half turn. Continue in the same manner, tightening each bolt/nut this time a quarter of a turn at a time until they are all tight. When giving away fasteners, you should also follow the described procedure, but in reverse order.

Disassembly of components

Disassembly of all components should be carried out in such a manner that, when reassembled, each part can be installed in its original place and in the correct way. Remember the characteristic features of the appearance, if necessary, make landing marking of parts that can be installed in place in an ambiguous way (such elements include, for example, a thrust washer fitted with a groove on the shaft). It is a good idea to place the removed parts on a clean surface in the order in which they were removed. It will also be useful to draw up the simplest schematic sketches or take step-by-step photographs of the component to be disassembled or removed.

When removing a fastener, try to mark its original position on the assembly. Often, immediately reinstalling fasteners and washers after removal of the corresponding part avoids confusion during assembly. If this is not possible, all fasteners should be placed in a box specially prepared for this purpose, divided into marked sections, or simply in separate marked containers. This course of action is especially useful when working with components that consist of many small parts, such as an alternator, valve train, instrument panel, or trim elements.

When disconnecting electrical contacts and connectors, individual wires or wiring harnesses should be marked with insulating tape with a numerical or letter code applied to it.

Sealing surfaces

On all vehicles, gaskets are used to seal the junction of the mating surfaces of two or more parts and serve to prevent leakage of oils and fluids and maintain high pressure or vacuum inside the assembly.

Typically, these gaskets need to be coated with a liquid or paste sealing compound prior to installation. Often, under the influence of time, temperatures or pressure, such a strong «sticking» to each other mating surfaces that the separation of parts becomes a difficult task. The disassembly of such nodes is helped by tapping them from the outside around the perimeter of the junction with a hammer with a soft striker. You can also use an ordinary hammer for this purpose, striking through a wooden or plastic spacer. Cast housings and fragile components should not be tapped. When this type of problem occurs, always check that all fasteners have been removed first. Try not to use a screwdriver or pry bar to separate the parts, inserting them between the mating surfaces, they are easily damaged, which can later cause leaks. If jerking «stuck» assembly elements cannot be avoided, use a wooden handle from an old mark for this purpose, but do not forget to carefully remove all chips from the mating surfaces and from the inside of the assembly.

After separating the parts, their mating surfaces should be carefully cleaned by scraping off the material of the old gasket from them. Hardened fragments of the old gasket can be pre-softened with a rust converter or a special chemical composition, and then removed with a scraper. In this case, a piece of copper tube with a flattened and pointed end can be used as a scraper. The use of copper tubing for this purpose is recommended, since copper is usually softer than materials used in a car, which reduces the risk of damage to the mating surface. Some gaskets can be easily removed with a copper brush, however, regardless of the method used, the mating surfaces should be completely clean and smooth. If for any reason the mating surface is scratched, fill the scratch with gasket sealant before assembling the components. In most cases, a non-curing or semi-curing sealant should be used.

Hose Removal Tips

Attention! Do not disconnect from air conditioning components (K/V) no hoses until the system has been deflated by a workshop technician.

The precautions to be taken when removing hoses are very similar to those when removing gaskets. Avoid damage to the surfaces of the fittings and tubes on which the hoses are put on, as this can cause leaks. In particular, this applies to the procedure for removing the hoses of the cooling system. Due to various chemical reactions, «sticking» rubber hoses to the mating surfaces of fittings and branch pipes. To remove the hose, first loosen the hose clamp on the fitting. Then grab the hose near the clamp with tongs with a sliding joint and begin to rotate it on the fitting or nozzle left and right. Continue this procedure until the hose is completely free, then remove the hose from the fitting. A small amount of silicone or other lubricant will make the procedure easier if it can be injected into the gap between the fitting and the hose. To facilitate the installation of the hose, grease the inside of the hose and the outside of the fitting.

As a last resort, or in the case of a clear need to replace the hose, you can cut the end of the hose from the fitting with a knife. At the same time, try not to damage the metal of the fitting or connecting pipe with a knife.

If the hose clamp is damaged, replace the clamp. Twist-type clamps usually loosen over time, so regardless of their condition, it is best to replace them with screw-type clamps on occasion.

Tool

The choice of a good tool is one of the basic requirements for anyone who plans to perform car maintenance or repair procedures on their own. At first glance, the costs associated with acquiring the required set of tools may seem too high, but when compared with the costs associated with the implementation of routine maintenance procedures and the simplest car repairs at a service station, they turn out to be quite reasonable.

Below are lists of the three toolkits. Vehicle owners who do not have practical mechanical experience should start by performing procedures limited to the use of tools from the first list, while improving their skills and gradually expanding the range of tools used. As you gain experience, you can move on to more complex tasks, complementing the set of tools at hand. After some time, the acquired skills will allow you to start performing more complex work that requires the use of a tool from the second list (for general and major car repairs). When the qualifications begin to allow you to save significant funds on the independent implementation of complex belt procedures, you can think about purchasing a special tool.

A set of tools for routine maintenance and minimal car repairs

The list below includes the minimum tools required to perform routine maintenance and minor vehicle repairs. It is recommended to purchase a set of combination wrenches (with a regular open end on one end and a flare on the other). Despite the high cost of such a set compared to the cost of a set of conventional wrenches, the costs will be justified, because. these keys have the benefits of both types.

• Combination wrench set 8 to 19 mm
• adjustable wrench (up to 35 mm)
• Candle wrench with rubber insert (petrol models)
• Gap adjustment tool (petrol models)
• Probe set
• Nipple wrench for bleeding brakes
• Screwdrivers:
• with a flat sting (100 mm long by 6 mm in diameter)
• With a cross sting (100 mm long by 6 mm in diameter)
• Combination pliers
• Hacksaw with a set of blades
• Tire Inflator
• Tire pressure gauge
• Grease gun (syringe)
• oil canister
• Fine sandpaper
• Wire brush
• Tool for stripping terminals and battery wire contacts
• Oil filter wrench
• Funnel (medium size)
• Supports for fixing the car in a raised position (2)
• Drainage tank

A set of tools for general and overhaul of a car

The tool listed below will be required when repairing a car engine and is offered in addition to the first list. This listing includes a complete set of interchangeable sockets. At a significant cost, a set of interchangeable heads brings invaluable benefits due to its versatility and ease of use - especially in combination with the various types of actuators included in the kit. It is recommended to use 1/2" drives preferably (not 3/8 inch), because they, although more expensive, can be used with almost any type of torque wrench (Ideally, a good mechanic should have both types of drives at his disposal). A cheaper alternative to a set of interchangeable sockets is a set of tubular wrenches.

Set of interchangeable sockets (including type heads «Torx») or tubular wrenches, sizes corresponding to the sizes of wrenches from the previous list

• Ratchet reversible drive (for use with interchangeable sockets)
• Gate length 250 mm
• cardan drive (for use with interchangeable sockets)
• torque wrench (with drive of the same size as for interchangeable sockets)
• Self-locking forceps
• Hammer with round face (about 230 g)
• Soft-faced hammer (plastic or rubber)
• Screwdrivers:
• with a flat sting (150 mm long and about 6.5 mm in diameter)
• with a flat sting (strong No. 2, 8 mm)
• With a cross sting (No. 3, 203 mm)
• With a cross sting (strong No. 2)
• Clamping pliers
• Pliers:
• For electricians (with insulated handles)
• narrow-nosed (needle nose pliers)
• For retaining rings (internal and external)
• Chisel 25 mm
• Scraper (made of flattened and pointed at one end of a copper tube)
• scriber (scriber)
• Kerner
• Beards with a thin sting (1.6, 3.2, 4.8mm)
• Hose clamp kit
• Brake bleeding kit
• Drill set
• Steel Ruler / Flatness Gauge
• A set of hexagon bar keys (for heads with internal hexagon)
• File set
• Wire brush (big)
• Second set of supports
• Jack (hydraulic or foot type)

Note. Another constantly required tool is an electric drill with a chuck up to 9.5 mm and a set of high-quality drills.

Special tool

This list includes tools that are sufficiently expensive, are not required regularly, or require following the instructions of the manufacturers of these tools when using. If your area of activity does not include the frequent performance of complex mechanical operations, the acquisition of such a tool will be a bad investment. It is reasonable to buy it in clubbing with friends or rent it in car service workshops.

The list includes only those tools that can be found in retail trade or that are produced for distribution to the representative offices of firms. Sometimes in the text of the Manual you can find references to such special tools. Usually, the authors try in parallel to propose an alternative method that avoids the obligatory use of a hard-to-reach tool. If it is impossible to avoid the use of a special tool, and acquiring it for use is problematic, it is better to entrust the performance of the relevant work to service station specialists.

• Valve spring compression tool
• Valve Lapping Tool
• Piston ring cleaner
• Piston ring crimping tool
• Piston ring installer
• Cylinder Compression Gauge (compression meter)
• Countersink for processing the edges of cylinders
• Hone for processing cylinder mirrors
• Cylinder diameter gauge
• Micrometer and/or dial caliper
• Clutch disc centering tool
• Ball joint puller
• Puller universal type
• impact screwdriver
• Dial meter set
• stroboscope (with inductive sensor)
• Manual combination pump (vacuum/pressure)
• Set of taps and lerok
• Tachometer/instrument for measuring the duration of the closed state of the contacts of the breaker
• Universal tester for electrical measurements
• lifting rigging
• Brake spring removal/installation tool
• cart jack

Purchasing a tool

When preparing for routine maintenance or minor vehicle repairs, it is wise to purchase the tool separately. On the other hand, in the case of planning extensive work, it is easier, safer and more cost-effective to buy a set of modern tools, which usually comes with a tool box. In the future, to expand the choice, you can buy individual tools, additional kits and a larger tool box. The gradual expansion of the set of tools will allow you to stretch the costs and decide on the choice of really necessary tools.

Specialized tool magazines are the only source for some specialty tools, but whatever the source, avoid cheap purchases, especially for screwdrivers and replacement sockets, as they will likely not last long. As a result, the costs associated with the replacement and restoration of a cheap tool will be incomparably more significant than the costs of a one-time purchase of a quality product.

Tool care and storage

A good tool is a valuable investment, so it is wise to take care to keep it clean and ready for use at all times. After using the tool, always thoroughly clean it of dirt, grease and metal particles before storing it. Never leave tools scattered around the work area. After completing the work, carefully check the area under the hood and under the car for the presence of a forgotten tool.

For storing tools such as screwdrivers, pliers, hammers, etc. a tool comb mounted in a convenient location on the garage wall is ideal. Sets of wrenches and interchangeable sockets should be stored in metal boxes. The measuring tool must be stored in a dry and clean place inaccessible to corrosion.

You should always pay attention to the condition of the working surfaces of the tool. The impact part of the hammer head is subject to riveting during operation, screwdrivers lose sharpening of their stings over time. Don't be stingy with spending a little time removing rivets and tidying up the cutting edges with sandpaper or a file. Replace irreparably worn or damaged tools.

With proper care, the tool will last for a very long time.

Workplace equipment

If more serious work is to be done than simple routine maintenance, care should be taken to prepare a suitable work site. An important requirement is the presence of a roof or awning.

If possible, any disassembly procedures should be done on a clean, flat workbench (table) convenient height, equipped with a vice. Sufficient is the presence of a vice with soft pads on the jaws, opening up to 100 mm.

As mentioned above, the job site should have a clean, dry storage area for tools, lubricants, cleaners, fillers, paints, etc.

Since an absolutely essential tool is an electric drill, therefore, the work site must be equipped with a power source to connect it.

Finally, the workplace should always have a sufficient supply of old newspapers and clean, lint-free rags for cleaning the work area, tools, and vehicle parts.

Never do any work on the exposed painted surface of the vehicle, use protective fender pads, or cover polished surfaces with old blankets.