Contents: Mating surfaces and gaskets ↡ Sealing cuffs ↡ Threaded connections ↡ Washers and anti-loosening agents ↡ Special tools and devices ↡ Environmental protection ↡
Observe the following rules when performing maintenance, repair or repair work:
Mating surfaces and gaskets
When disassembling mating parts, never separate screwdrivers or similar tools between them. This can cause serious damage, which after assembly ends in leaks of oil, coolant, etc.
Separation is usually accomplished by tapping along the mating surfaces with a soft hammer to dislodge or break the gasket. However, it should be noted that this method is not suitable for disassembling pinned joints.
If a gasket is required between the mating surfaces of two parts, a new gasket should always be installed during assembly; install a dry gasket unless otherwise stated in the assembly manual.
Before installation, make sure that the mating surfaces are clean and dry and free of old gasket material. When cleaning the mating surfaces, use a tool that will not damage the surface and remove any burrs or nicks with an oiled abrasive block or a fine file.
Make sure 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 clear, blow them out with compressed air.
Sealing cuffs
The cuff can be removed by prying it up with a wide-head screwdriver or similar tool. Alternatively, you can screw several self-tapping screws into the cuff and pull the cuff out using them with pliers.
In any case and regardless of the reason for removal, the removed cuff should be replaced with a new one upon installation.
A fine new seal can be easily damaged and will not perform its function 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 some movement of the seal relative to the surface, the part must be replaced. Protect the working lips of the seal from contact with any parts that may damage them during installation. Use tape or a tapered mandrel if possible. Lubricate the seal with oil before installation.
When installing a cuff with two edges, seal the space between them with consistent grease.
Unless otherwise specified, seals must be lubricated with the oil they are intended to prevent leakage when installed.
To press the cuff into the housing, use a ring mandrel of the appropriate size or a wooden block. The cuff should be installed flush with the housing surface (unless otherwise stated).
Threaded connections
Nuts, bolts, and screws are common places where corrosion occurs. If a threaded connection does not unscrew, wet the connection with liquid oil, kerosene, or another 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 gently heating the connection. If this does not help, you will have to resort to using a hacksaw or chisel.
Studs are usually removed in the following manner. Screw two nuts together onto the stud and tighten them well. Then, using a wrench, turn the lower nut to loosen the stud. Studs or bolts that have broken below the surface of the part into which they were screwed can sometimes be removed with a stud extractor. Before screwing a stud or bolt into a blind hole, first make sure that the hole is completely clear of oil, grease, water or other liquid. Failure to do so may result in the housing collapsing due to the increased hydraulic pressure that the bolt or stud creates when screwed 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 cotter pin holes unless specifically instructed to do so in the assembly instructions.
If you need to check whether a bolt or nut is tightened correctly, loosen it a quarter turn, then tighten it again to the required torque using a torque wrench. However, this should not be done if the connection has been tightened to the required angle after tightening with a torque wrench.
For some threaded connections, especially cylinder head bolts or nuts, the final tightening step is not a torque, but an angle to which the fastener must be tightened. Usually, a fairly low torque is specified for tightening the bolts in a certain sequence, then the final tightening is done in one or more steps by the specified angles.
Washers and anti-loosening agents
Any fastener that is required to rotate relative to a component or housing when tightened should always have a washer between it and the component in question.
Spring or split washers should always be replaced in critical connections such as the big end of the connecting rod.
Bend washers should also always be replaced if they have been bent back even once to free a nut or bolt.
Self-locking nuts can be used repeatedly in less critical connections if resistance is felt when tightening, when the locking part of the nut enters the thread of the stud or bolt. However, it should be noted that self-locking nuts gradually lose their effectiveness with prolonged use and they also need to be replaced periodically.
Cotter pins should always be replaced with new ones of the correct size for the hole.
If anaerobic sealant or other anti-loosening compound has been applied to the threads, it should be washed off with solvent and a wire brush, and fresh compound should be applied during assembly.
Special tools and devices
Some repair procedures described in this manual require the use of special tools and devices such as presses, two- or three-jaw pullers, spring compressors, etc. Wherever possible, suitable substitutes for the special tools are described. In some cases, where no alternative is possible, it is necessary to use the original tool for safety reasons and to improve the quality of the repair. If your qualifications are not very high, or if you have not fully understood the procedures described, never attempt to do without the use of the special tool (devices), if the procedure described involves its use. Not only can you get injured, but you can also damage expensive parts.
Environmental protection
When changing oils, brake fluid, antifreeze, etc., it is necessary to take measures against environmental pollution. For example, do not pour any of the above-mentioned liquids into the general sewer or on the ground, where they can be absorbed. There are many collection points for used oils and other liquids. Each garage or guarded parking lot should have a special collection point for such liquids.
Due to the ever-increasing tightening of legislation in the field of environmental protection, in particular, the reduction of air pollution by motor vehicles, many cars have devices for protecting the most important places of fuel system adjustment. These protective devices are intended primarily to prevent unqualified interference in the adjustment of air-fuel mixtures, which can cause an increase in the toxicity of exhaust gases. Such protections must be restored after repair, in accordance with the manufacturer's requirements or current legislation.