Mating surfaces and gaskets
When disassembling mating parts, never separate screwdrivers or similar tools between them. This can lead to serious damage which, after reassembly, results in leakage of oil, coolant, etc.
Separation is usually done by tapping along the mating surfaces with a soft mallet to move or break the gasket. However, keep in mind that this method is not suitable for disassembling pinned connections.
If there must be a gasket between the mating surfaces of two parts, a new gasket should always be installed during assembly; install a dry gasket unless the assembly manual says otherwise.
Before installation, make sure that the mating surfaces are clean and dry and that there are no traces of the old gasket on them. When cleaning the mating surfaces, use a tool that will not damage the surface and remove any burrs or nicks with an oil-filled abrasive stick or fine file.
Make sure that all threaded holes are clean and do not allow liquid sealant to enter them, unless otherwise specified in the assembly instructions.
Make sure all holes, channels or pipes are clean, blow them out with compressed air.
Sealing cuffs
The cuff can be removed by prying it out with a wide-end screwdriver or similar tool. Alternatively, you can screw a few self-tapping screws into the cuff and pull out the cuff using pliers.
The removed cuff in any case and regardless of the reason for the removal, should be replaced with a new one during installation.
A new fine cuff can be easily damaged and will not perform properly if the surface it contacts is not completely free of scratches, nicks or grooves. If the surface of the part cannot be restored and the manufacturer has not provided for some movement of the seal relative to the surface, the part must be replaced. Protect the working edges of the cuff from contact with any parts that could damage them during installation. Use a tape or cone if possible. Lubricate the cuff with oil before installation.
When installing a seal with two lips, plug the space between them with grease.
Unless otherwise specified, the seals must be lubricated with the oil they prevent from leaking during installation.
Use an appropriately sized ring mandrel or block of wood to press the collar into the housing. The cuff must be installed flush with the body surface (unless otherwise specified).
Threaded connections
Nuts, bolts and screws are common places where corrosion occurs. If the threaded connection does not loosen, moisten the connection with liquid oil, kerosene or similar liquid and leave it for a while. You can try using a screwdriver or an impact wrench. If none of these methods help, you can try warming up the connection gently. If this does not help, then you will have to resort to using a hacksaw or chisel.
Studs are usually removed in the following way. Screw two nuts onto the stud together and tighten them well together. Then, turning the lower nut with a wrench, unscrew the stud. Studs or bolts that have broken below the surface of the part they were screwed into can sometimes be removed with a stud extractor. Before driving a stud or bolt into a blind hole, first make sure the hole is completely free of oil, grease, water, or other liquid. If this is not done, the housing may be destroyed due to the increased hydraulic pressure that the bolt or stud creates when screwing in.
When tightening the castle nut, tighten the nut to the specified torque, then tighten it to the next cotter pin hole. Never loosen the nut to align the pin holes unless specifically instructed to do so in the assembly instructions.
If you need to check the correct tightening of a bolt or nut, unscrew it (her) a quarter turn, then tighten again to the required torque using a torque wrench. However, this must not be done if the connection, after tightening with a torque wrench, was still tightened to the required angle.
For some threaded connections, especially for cylinder head bolts or nuts, the last stage of tightening is not indicated by the torque, but by the angle by which the fastener must be tightened. Typically, a fairly low torque is specified to tighten the bolts in a certain sequence, then one or more turns are made to the specified angles.
Washers and means against self-unscrewing
Any fastener that needs to be rotated relative to a part or housing when tightened must always have a washer between it and the corresponding part.
Spring washers or split washers should always be replaced in critical connections such as the bottom end of the connecting rod.
Folding washers should also always be replaced if they have been bent at least once to loosen a nut or bolt.
Self-locking nuts can be reused in less critical connections if resistance is felt during tightening when the locking part of the nut comes into the thread of the stud or bolt. However, it should be noted that self-locking nuts gradually lose their effectiveness with prolonged use and must also be replaced periodically.
Cotter pins must always be replaced with new ones that fit the hole.
If an anaerobic sealant or other anti-twist compound has been applied to the threads, it must be washed off with a solvent and a wire brush, and fresh compound should be applied during assembly.
Special tools and fixtures
Some of the repair procedures described in this manual require the use of special tools such as a press, two or three jaw pullers, spring compressors, etc. Wherever possible, suitable substitutes for special tools are described. In some cases, where no alternative is possible, it is necessary to use a proprietary tool for safety reasons and to improve the quality of the repair. If your qualifications are not very high, or if you have not achieved a full understanding of the procedures described, never try to get by without using a special tool (fixtures), if the described procedure calls for its use. You can not only get injured, but also ruin expensive parts.
Environment protection
When changing oils, brake fluid, antifreeze, etc., measures must be taken against environmental pollution. For example, do not pour any of the above fluids into public sewers or onto the ground where they can be absorbed. There are many collection points for used oils and other liquids. On the territory of each garage or guarded parking lot there should be a special collector for such liquids.
In connection with the ever-increasing tightening of legislation in the field of sewing up the environment, in particular, reducing air pollution by motor vehicles, many cars have protection devices for the most important places for adjusting the fuel system. These protective devices are primarily designed to prevent unauthorized intervention in the adjustment of air-fuel mixtures, which can cause an increase in exhaust emissions. Such protections must be restored after repair, in accordance with the requirements of the manufacturer or current legislation.