As a rule, a gasket is only used once. So make sure that you have the spares you need before you start the job. We are limiting ourselves to inactive gaskets which are those that are firmly bolted between two parts, to seal against each other and/or to stop something escaping into the environment. After asbestos was outlawed for all times as a gasket material, there are still a number of materials suitable for the job: from paper to cardboard or fiber materials of all types. In contrast to the parts to be sealed, the gasket-volume is not maintained when the parts are bolted together, the gasket material is compressed. This property can be very useful if, e.g., a spare part is no longer available. In this case, one would lay a sheet of gasket material having a similar consistence and thickness on the surface to be sealed, then using a light hammer, on can gently punch out the thread-holes. After that, it's simply a case of cutting it to size.

Which side of the gasket comes where?, this is important, also when using production gaskets. Should the surface be asymmetrical, it's easy to place the gasket correctly. If however, the gasket will fit from both sides, one should pay attention to the printing on one side, this is also quite often in English. It's possible, that one side of the gasket is, e.g., better protected against heat, which if incorrecty installed, could cause it to mal function after a short period. Pay close attention to the thread-holes and any other openings in the gasket. Sometimes a passsageway has been intentionally reduced. If you should accidentally make this error, severe damage, e.g., through the loss of lubrication can be the result. The best thing to do is, keep your eyes open during the fitting.

It's good, if the exact position of the cover to be mounted is predetermined by dowel-pins, and dicey if the gasket can easily be shifted out of alignment. Sometimes the covers can be bought as spare parts with the gasket already integrated. An unsuccessful installation attempt is always very unfortunate. In this case, it could mean a great deal of work, before one even gets the chance to change the gasket again. Possibly, one has to catch up the oil which has leaked out, or even do an oil-change, in all cases, a new gasket must be bought, only then can one try again. Sometimes the testing for internal leakage is also difficult. The cylinder head has several areas which have to be sealed.

If we assume that flat-gaskets are compressed, then of course, the even tightening of bolts or screws, in the correct order and nowadays, using the correct torque, is very important. This however, can only be valid if all the threads are in good condition. A certain stiffness takes away much needed contact pressure at the prescribed torque. 03/12