1. Scratch out all traces of material of old laying from the interfaced surfaces of a head of cylinders. Be careful, try not to damage components.
2. Scratch out coal deposits from walls of combustion chambers, and also inlet and final ports of a head. Carefully wash out a head kerosene or other suitable solvent.
3. Scratch out the main layer of coal deposits from the surfaces of valves, then manually smooth out plates and cores of valves a wire brush.

1. Attentively check a head of cylinders for existence of cracks, traces of leak of cooling liquid and other damages. The burst head is subject to replacement without fail. In case of lack of confidence in definition of a condition of a head, it is necessary to address for the corresponding consultations in a workshop of car service.
2. By means of the planeness measuring instrument (the steel ruler put on an edge) and the probe of lezviyny type check the interfaced head surface for existence of signs of deformation. If not planeness exceeds admissible value (see Specifications), it is necessary to give a head to a pro-point in a mechanical workshop, or to replace it (in case machining gives to reduction of height of a head below of an admissible limit).

On diesel engines if when machining from a head more than 0.1 mm of height are removed, it will also be necessary to pierce combustion chambers and saddles of valves for the purpose of preservation of the proper dimensional correlations when landing plates of valves and guides of plugs.

3. Check a condition of saddles of valves in each of combustion chambers. In case of identification of cavities, cracks or traces of a progar, the head should be subjected to special recovery repair which performance lies outside qualification of the average amateur mechanic and it has to be entrusted to specialists of car service. If only insignificant defects are revealed, they can be eliminated in the course of performance of grinding in of valves (see below).
4. In case of wear of the directing plugs which characteristic sign is the excessive side side play of valves which is followed by dense blue smoke on an exhaust during the operation of the engine plugs are subject to replacement. Measure diameters of cores of the cylinders of valves removed from a head (see below), and also internal diameters of the directing plugs. The gap of landing of valves in plugs is defined by way of subtraction of results of the first measurements from the corresponding results of the second. Compare results of calculations to requirements of Specifications. If the size of landing gaps exceeds the limit of admissible range, it is necessary to make replacement of valves / their guides of plugs. Performance of replacement of plugs will be more correct to be charged to specialists of car service at whose order there are all necessary tools.
5. Restoration of saddles of valves is made only after replacement of the directing plugs.

6. On diesel engines check vortex cameras for existence of progar, cracks and other damages of this sort. Existence of small threadlike cracks in walls of cameras is admissible. Replacement of cameras is made only in cases of serious progar, deformations or weakening of landing in a head and has to be charged to experts of a workshop of car service. By means of the dial measuring instrument of plunger type measure height of a vystupaniye of vortex cameras. Nullify the measuring instrument, having rested a plunger against a pro-masonry surface of a head, then transfer it to a camera end face. Compare results of measurements to requirements of Specifications. If height of a vystupaniye of vortex cameras exceeds admissible value, it is necessary to address for council experts service center of the Citroyon company.

1. Check plates of valves for existence of cracks, cavities and traces of a progar. Estimate extent of operation of cores of valves. Check whether there are no cracks in necks of cores. By rotation check valves for a bend of cores. Make sure of lack of cavities and signs of excessive wear of end faces of cores. Identification of any of the listed defects demands replacement of valves.

2. If during conducting the check described above the condition of valves is recognized as satisfactory, measure a micrometer diameters of their cores in several points. Any noticeable difference in results of the measurements performed for each of valves indicates wear of its core and need of carrying out replacement.

3. The valves recognized suitable for further use have to be ground in to the saddles for a guarantee of tightness of closing of combustion chambers. If defects of a surface of saddles are only insignificant, they can be eliminated in the course of performance of such grinding in. Necessary smoothness of polishing of a surface of saddles after their recovery pro-point can be reached only when using special pritirochny pastes. In case of detection of deep defects or progar of saddles the condition of a head of cylinders and valves has to be checked by the expert who then makes the decision on the volume of recovery work or even replacement of valves or their saddles.
4. For performance of grinding in establish a head upside down on a strong workbench.

5. Apply a little pritirochny paste of the required granularity on a valve saddle surface, then fix a sucker of special pritirochny adaptation on an external surface of a plate of the valve. Reciprocating rotary motions of adaptation begin to grind in the valve to the saddle, from time to time, raising it for the purpose of paste redistribution. Placement under a plate of the valve of a weak spring will help to facilitate implementation of the procedure significantly.

6. When using coarse-grained pritirochny paste try to achieve dim opaque coloring of the ground-in surfaces of the valve and its saddle. Having received satisfactory result, wipe surfaces and repeat the procedure with use of more fine-grained paste. Grinding in can be considered finished when on working surfaces of a saddle and a plate of the valve smooth equal continuous rings of opaque light gray color appear. It is not necessary to continue grinding in longer, than it is really necessary in order to avoid excessive understating of a working surface of a saddle.
7. Having finished grinding in of all valves, remove with pure rags all traces of paste. Before assembly wipe surfaces with kerosene.

1. Check valvate springs for existence of mechanical damages and traces of an overheat (coloring change). Whenever possible compare the free length of the removed springs to length of new.
2. Establishing each of springs vertically on a flat surface, check severity of their tortsovka. Springs with violation of a tortsovka, it is equal as weakened and sunk, are subject to replacement. Replacement of springs is usually made in a set and, whenever possible, without fail.
3. Replacement of maslootrazhatelny caps of cores of valves is made also without fail, regardless of their state.