When removing screws, studs and nuts from a part, remember the locations where they were removed. Tighten the bolt back into place on the part or install the washer and nut back onto the stud to prevent them from being misplaced later. If this is difficult, store them in small boxes; tins, candy boxes and egg cartons are ideal for this purpose; each recess can be used to place bolts and nuts from a specific part of the part. Containers of this type are useful when working with assemblies and very small parts, such as a carburetor. Mark each recess with paint or stripes to indicate the parts.
When disconnecting plugs between two wire harnesses or even two wires, it is recommended to mark the two halves with numbered pieces of tape or a couple of pieces of colored tape of the same color - this will make it easy to connect them correctly later.
Surfaces sealed by a gasket (removing gaskets)
Gaskets seal the mating surfaces between two parts to prevent lubricants, fluids, vacuum, or pressure from leaking between them. Gaskets are often coated with a liquid or paste gasket sealant before the parts are assembled. Age, heat and pressure can cause parts to "stick" together so strongly that they are difficult to separate. Often this "grabbing" can be relieved by hitting the mating surfaces with a soft-faced hammer. You can use a regular hammer if you place a block of wood between it and the part, but do not hit cast or fragile parts with a hammer, as they can be easily damaged. If the part does not come off, look for a bolt or nut that you forgot to remove.
Do not use a screwdriver or pry bar to pry the parts apart. This can easily damage the gasket surfaces of the parts, which must be smooth to ensure proper sealing. If leverage is absolutely necessary, use the wooden handle of an old brush or a hardwood rod.
After separating the parts, carefully scrape off the old gasket and wash the sealing surface. Some gaskets can be removed with a wire brush. If any gasket material does not come off, soak it in a rust penetrating agent or treat it with a special substance to soften it, then scrape it off. A scraper for this purpose can be made from a piece of copper tubing, flattening and sharpening one of its ends. Copper is usually softer than the surface being cleaned, which reduces the likelihood of damage to the part. After finishing, the mating surfaces should be clean and smooth. If the surface sealed by the gasket is scratched, then when assembling the parts, cover them with a sufficiently thick layer of sealant. For most surfaces, use a non-drying or semi-drying gasket sealer.