Jeep Grand Cherokee

Carefully clear a head () cylinders and components клапанного the mechanism, then make check (their) its condition that will allow to define volume of a necessary recovery work on клапанному to the mechanism during performance of major repairs of the engine.

Scratch out all traces of a material of an old lining and hermetic from interfaced surfaces of a head, the inlet pipeline and a final collector. Try not to damage thus a head. The special solvents which application allows to soften a lining material are issued - ask in shops of automobile accessories. Remove from охладительных channels all traces of a scum. Small apertures clean by means of a special rigid brush - ершика. All carving apertures banish a tap of the corresponding size, having removed corrosion and hermetic traces and having restored the damaged coils. In the presence of access to a source of compressed air blow apertures, having removed from a bottom a shaving and small dust.

Rigid brush clean carvings of basic bolts коромысел. Wash out a head solvent and carefully dry it. Application of compressed air will allow to reduce essentially process of drying of a head and will give a guarantee of qualitative procleaning of all channels, apertures and remote cavities.

Wash out коромысла, their basic bolts, or spherical support, fixing nuts or bolts and bars of pushers in solvent, then carefully dry them (remember necessity of installation of all components at assemblage on the former places - try not to mix a detail during cleaning). Application of compressed air will help to reduce process of drying of components and will provide carefulness of a purge of apertures and channels. Wash out in solvent all клапанные springs, their saddles, crackers, plates (or rotary support), then carefully dry them. Make cleaning of components of each of valves serially for the purpose of maintenance of a guarantee of possibility of their installation at assemblage on the former places. Scratch out the thickest layers of adjournment from surfaces of plates of valves, then absolutely smooth out valves (both plates and cores) by means of a wire nozzle on an electrodrill. Again watch to mixing components.

Carefully check up a head on presence of cracks, traces of leaks of a cooler and other damages. In case of detection of cracks it is necessary to replace a head (in case of impossibility of its restoration - consult in a car-care centre workshop). By means of a planeness measuring instrument (an edge of a steel ruler) and probeа лезвийного type estimate degree of deformation of an interfaced surface of a head. If неплоскостность exceeds admissible value under Specifications, it is necessary to give a head in проточку to a car-care centre workshop.

Carefully survey saddles of valves in each of combustion chambers. In case of revealing on them of cavities, cracks or прогаров, the head demands carrying out of service of the valves which performance lies out of limits of qualification of the average mechanic-fan. Define a backlash between cores of valves and walls of directing plugs, having measured for this purpose size cross-section люфта a core of the valve by means of fixed on a head циферблатного a measuring instrument плунжерного type. The valve should be in the directing plug and on distance approximately 1,6 mm from the saddle. The measured value of size люфта for backlash definition should be divided into two. If after performance of measurements there are any doubts in correctness of an estimation of a condition of directing plugs of valves, they should be delivered for more exact check in a car-care centre workshop (cost of such check should be insignificant). If the backlash is excessive, directing plugs are subject to replacement.

Carefully check up a working surface of a plate of each of valves on presence of signs of non-uniform deterioration, deformations, cracks, cavities and прогаров. Check up cores of valves on presence задиров, agnails and the wiped sites, necks of cores check up on presence of cracks. Повращав the valve, make sure of absence of signs of a bend of a core. Check up a core end face on presence of cavities and signs of excessive deterioration. Presence of any of the listed defects speaks about necessity of carrying out of service клапанного the mechanism in a car-care centre workshop.

Check up each of valves on presence of signs of deterioration and damages to the specified points

Measure width (height) of a cylindrical part (corbel) of a forming surface of a plate of the valve. If the width of a corbel any of valves lies below an admissible limit under Specifications, the valve is subject to replacement without fail.

Check up end faces клапанных springs on presence of cavities and deterioration signs. Measure free length of springs and compare results of measurements to requirements of Specifications to the given Chapter. If any of springs it appears more shortly admissible value it is considered "given" and to the further use is not subject. To recognise springs suitable for installation on the restored engine it is necessary to make check of effort of their compression (in a workshop of car-care centre by means of the special equipment).

Establish each of springs on a flat surface and check up its quality торцовки. All deformed or "given" springs are subject to replacement without fail. Installation of springs with broken торцовкой conducts to the accelerated deterioration of directing plugs.

Check up plates of springs (or rotary support) and crackers on presence of cracks and deterioration signs. All components which are in a doubtful condition should be replaced new in order to avoid development of defects during operation of the restored engine.

Check up working surfaces коромысел (areas of contact with end faces of bars of pushers and cores of valves) on presence of cavities, attritions, задиров, roughnesses and deterioration signs. Also examine contact surfaces коромысел and their spherical support. Check up everyone them коромысел with a bolt and a nut of its fastening on presence of cracks. Check up end faces of bars of pushers on presence протертостей and traces of excessive deterioration. Take for a drive pushers on a flat surface (a large splinter of a windowpane) for revealing of their bend. Check up болтовые apertures on fastening коромысел in heads of cylinders on presence of damage of coils of a carving. All damaged or excessively worn out components are subject to replacement. If in the course of survey are revealed a bad general condition клапанного the mechanism and deterioration of its components over admissible limits that is the normal phenomenon in the engine demanding major repairs, establish components клапанного the mechanism back in a head and familiarise with recommendations about carrying out of service of valves (Has undressed Service of valves).