You will need
- - a set of flat probes;
- - special pattern or fitting a wide range;
- - paste for lapping;
- device for lapping valves.
In order to verify tightness of valves, remove the cylinder head (cylinder head), then clean it and the bearing housings, in which often accumulates soot and dirt. Also remove any deposits of oil and using a metal brush, clean the carbon deposits from the walls of the combustion chambers.
Inspect the cylinder head and bearing housing to ensure no cracking. Also check the camshafts, the bearing holes of hydrotalcite and bearing for signs of covering metal. Note how tightly the guides and valve seats sit in the cylinder head. Make sure that there are no traces of displacement when running naturally aspirated. Check valve and seat on the absence of traces of burning and cracks.
Using a special pattern, check flatness of cylinder head. If such a template is missing, use a wide metal ruler and check the lower mating plane of the head.
To check flatness, place a ruler to the plane of the head. Make sure that between its edge and the plane, with no gaps. Inspect the entire plane, since the gaps can be in the middle and at the edges. The gap should not be more than 0.01 mm. If it is greater than this value, the mating plane of the head will need to progressirovanii or replaced. To change the cylinder head must, together with the bearing housing.
Also check the head for leaks. To do this, close the window coolant to the thermostat from the face surface of the head, and then cut from a piece of rubber gasket and place it under the elbow of the thermostat. Then flip the head and fill it with kerosene all the internal cavities designed for coolant.
Valves also need to be checked tightness. To make it easy. To do this, put the head unit on a level surface so that its mating surface is facing up. Then pour in the combustion chamber the kerosene and wait a few minutes. The decrease in the level of kerosene in one of the cells means that one or both valves are leaking.
Inspect the cylinder head for leaks. If leaks or sinks found on the mating plane of the head, to repair it will be possible only with the use of cold welding. If desired, it can be replaced.
Elimination of leakage of valves can be made by lapping. But this method can be applied only in the case if the seat and the valve plate has no cracks, ruts and other mechanical damage.