1. Pre-piston connecting rod assembly should be thoroughly cleaned. Piston rings must be removed.  | Piston rings are subject to replacement without fail. |
2. Using the special adaptation remove rings from pistons, - try not accidentally damage the walls of the latter.
3. Scrape the bottom of the piston with traces of carbon deposits. After removal of the base layer of sediment smooth out the surface by hand with a wire brush or a piece of fine sandpaper. | In no case do not use strippers made of soft material and pistons easily subject to erosion wire nozzles to an electric drill! |
4. Using the special adaptation clean flutes under installation of rings on the pistons. Alternatively you can use for this purpose a fragment of an old piston ring, but be careful - do not scratch the floor and walls of the groove and cut fingers. 5. Remove the main deposits, connecting rod assembly wash solvent and carefully dry them, whenever possible with the use of compressed air. Check patency maslovozvratnyh hole in the rear grooves for installation of piston rings, and oil holes in the bottom heads of rods.  | When using compressed air do not forget to wear safety goggles! |
6. If the walls of the piston and bore is not damaged and excessively are not worn and do not eat through the engine block and does not replace the need to replace the pistons also disappears. Normal wear pistons shown as vertical tracks by making the abutment surface and a small slack fit of the upper compression ring in its groove. Do not forget that replacement of piston rings is made without fail, regardless of their status.
7. Inspect each of the pistons for cracks in a skirt around ledges under installation of piston pins and the area of the rings.
8. Check the thrust surface of the piston skirt for scratches, the bottom - on presence of through holes and burnouts on the edge. The presence of scratches on a skirt can be seen as a sign of long-term engine overheating or too early ignition of air-fuel mixture - Check the operation of the cooling system. Burnouts along the edges of the bottom are evidence of detonation. In any case, the cause of the identified violations should be eliminated in order to avoid relapse. The possible causes of these defects can act as the intake air leakage, improper layout of the air-fuel mixture, a violation of the ignition timing, ignition systems malfunction and EGR.
9. Pitting pistons in the form of cavities speaks about hit in the combustion chamber and / or the crankcase of the engine coolant. Again, take care that the cause of internal leakage was eliminated.  | 10. Rate the value of backlash of landing of piston rings in their grooves, which enclose a new ring outside in the flute on the piston and the feeler blade, measure the remaining gap. Repeat the measurement at two or three points on the perimeter of the groove. Be careful not to confuse the compression ring - the top is different from the second. If the clearance exceeds the limit (see. Specifications), the pistons must be replaced. |
11. Determine the planting gap pistons in their cylinders, which measure the diameter of the latter (see. Section Checking the status of the unit) and subtract from their respective diameters of the pistons. Measurement of the diameter of the piston is carried by the thrust surface at an angle of 90 ?� to the piston pin axis and at a predetermined distance from the bottom. If planting gap piston in the cylinder exceeds the limit (see. Specifications), the unit should be given in the groove with a selection of new pistons and piston rings repair diameter.  |  |
12. Rate the correct seating of the pistons on rods, trying to roll the ingredients in opposite directions. Have any noticeable backlash indicates excessive wear of joints. To correct the situation, connecting rod and piston assembly must be delivered in a workshop service center, which will make necessary regenerative repair and replacement fingertips.
13. Implementation procedures for removing pistons with connecting rods (in case the need arises) should also be entrusted to experts of car-care center. In parallel, the connecting rods can be checked for signs of bending, twisting and other deformations using special diagnostic equipment. | Without the need should not be removed from the piston rods. |
14. Check the cranks for cracks and other mechanical damages. Temporarily remove the covers of the bottom heads, remove the shells of old bearings, wipe the bed cover and a head and inspect for burrs, rough edges and burrs. Having finished check, insert liners in place, install the cover on the bottom heads of rods and by hand tighten the mounting bolts. | If the engine is being repaired to eliminate knock fingers, replace the connecting rod assembly. |
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