| 1. Before testing connecting rods and pistons should be cleaned and removed from the old piston rings. |
 | 2. Carefully spread the ring, shifting the top of the piston. When removing the ring from falling into the empty groove, run under the ring two or three old probe. |
| 3. Scrape carbon deposits from the piston crown. After removing the top layer of coarse sludge clean the piston crown by hand with a wire brush (or sandpaper on the basis of cloth). |
| 4. Carefully remove the carbon deposits from the grooves of the pistons using old broken piston ring. |
| 5. Clean the piston and connecting rod assembly in a solvent, thoroughly dry. Ensure clean grooves to drain the oil in the grooves under piston rings. |
| 6. Measure micrometer diameter of the piston perpendicular to the axis of the piston pin (at a given distance from the edge of the piston skirt) and compare the result to the standard. Size group piston stamped on its bottom. If the wear exceeds the maximum permissible piston, the piston must be replaced. |
| 7. Check the clearance between the piston ring and the piston groove wall. For this insert ring with an outer side and a corresponding groove in the probe to measure the gap between the upper surface of the ring and the wall of the groove. If, even with the new ring backlash exceeds norm replace the piston. |
| 8. Check for clearance at the junction of the piston rings, which insert the ring into the corresponding cylinder and push the piston bottom to avoid bias in the measurement of the ring. Push the ring to a depth at which the edge of the piston skirt becomes equal to the split plane of the cylinder block, then remove the piston. Measure the clearance probe. If the clearance is excessive, replace the ring and repeat the procedure. If the clearance exceeds the norm with new rings, the cylinder should be chiseled and othonningovat (cm. Subsection 3.1.2.10). |
| 9. Carefully inspect for cracks on the piston skirt for the piston pin bosses and the spaces between the piston ring grooves. |
| 10. Check for chips and burrs on the friction piston skirt area, traces of erosion on the edges of the bottom. If there are chips and burrs, it indicates frequent engine overheating, one of the reasons which may be abnormal combustion of the fuel mixture. In this case a thorough inspection of power supply systems, lubrication and cooling. Traces of melting the side surface of the piston show breakthrough gases from the combustion chamber. Burnout piston head or charred areas on the edges of the bottom point to the abnormal operation of the engine because of improper installation of the ignition timing (too early ignition), or as a result of the detonation. If these flaws are found, it is necessary to find the cause and fix, otherwise manifestation of the reasons for this deterioration is possible in the future. The reasons for abnormal operation of the engine can be air leak in the intake manifold, incorrect installation of the moment of ignition, fuel injection system failure. |
| 11. Corrosion of the piston in the form of small pits (pitting) indicating that the penetration into the combustion chamber (and in the crankcase, crankshaft) of the coolant. Here again, you want to find the cause and eliminate. |
| 12. Carefully check the existence of such damage to the rods as cracks on the heads about piston pin and connecting rod bearing installation sites. Check whether there is a deformation of the body of the connecting rod (twisting or bending). Damage to the rods and is unlikely occurs only in the case of jamming or excessive engine overheating. Thorough check rods can only be performed in the workshop, where there is the necessary equipment. |
| 13. If necessary, the piston can be removed from the rod and assemble the connecting rod as follows. |
 | 14. Remove the retaining ring piston pin and push the piston Palais. If necessary Abut the piston and gently shake a finger strokes molotkapo mandrel. |
 | 15. Removing the piston pin is much easier when the piston is heated to 60-70 ?� C. |
| 16. Verify that the piston pin and the hole in the head of a rod signs of wear or damage. Check the clearance in the piston pin and connecting rod. |
| 17. If the sleeve connecting rod and piston pin are worn out, or if the gap finger in a rod head exceeds the norm, the pin and the bushing should be replaced. Replacement plugs of heads of rods should be carried out in the workshop. |
| 18. If the clearance between the piston and the finger is much higher than normal, the piston and the pin should be replaced complete. Keep in mind that the clearance between the piston and the finger does not play such an important role in the clearance of the connecting rod head. |
| 19. The connecting rods themselves do not require replacement, except in cases of jamming of the engine, or other serious damage. Check the condition of the connecting rods inspection, upon detection of deformation of rods and take them to the shop for auto-service inspection and repair. |
| 20. Purchase new parts to replace worn-out. |
| 21. Align the piston and the connecting rod so that the groove on the piston, which is intended to face towards the front of the engine (in the form of an arrow or a dash) is correctly positioned relative to the oil hole in the rod body (see. Fig. Correct orientation of the reciprocal piston rod) . With proper mutual orientation of the label on the piston should be turned toward the front of the engine, and the oil hole in the body of the connecting rod should be turned toward the rear of the cylinder block. |
 | 22. Lightly lubricate the piston pin with fresh engine oil and insert it into the hole in the piston and rod head. If necessary, place a finger on the face down easy blows of a hammer on the mandrel. |
A warning  In order to facilitate the installation of the piston pin heat the piston.
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 | 23. Check up freedom of rotation of the finger in the piston lugs, and then install the retaining ring into the groove of the piston. |
