| 1. Carefully remove the ring from the piston using a special device. |
| 2. When removing the rings do not damage the surface of the piston. If there is no special device, the ring can be removed with the help of old probe or equivalent narrow metal strips. Carefully spread the ring enter between the ring and the piston plate, remove the ring, moving it on plates. |
| 3. Repeat the process with the other ring, avoiding to fall into the lower ring located above the groove. Since the ring must be replaced, it is their accidental breakage should be ignored, but the experience gained when removing the rings, is very useful when installing the new rings on the piston. |
| 4. Scrape carbon deposits from the bottom of the piston. After removing the top layer of coarse sludge, piston crown clean brush or sandpaper on the cloth basis. No way, not removed the remains of a deposit with a wire brush, impaled on a power drill, as this may lead to the erosion of the soft alloy from which the cast pistons. |
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| 5. Use the special tool to remove carbon deposits from the piston ring grooves. If such a device is not available, you can use the old broken piston ring. Remove only the deposits, while respecting careful not to remove the piston material. Try not to damage the sealing surfaces of the groove rings. Beware of cuts as sharp edges of the broken ring. |
| 6. After removing the sludge, wash the surface of the ring groove solvent, dry thoroughly. Ensure clean oil drainage grooves in the place of installation oil ring. |
| 7. If there are no signs of significant wear and if the cylinder bore is not required, the pistons should not be changed. Normal wear manifests itself in the form of the uniform vertical development in the friction of the piston and a slight easing of landing the top compression ring. Replacing the piston rings is required. |
| 8. Carefully inspect for cracks on the piston skirt for the piston pin bosses and landings of piston rings. |
| 9. Check for chips and burrs on the friction surface of the skirt portion of the piston, traces of burnout in the central part of the piston crown, as well as the erosion of his crown. 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 careful check of the lubrication and cooling systems. |
| 10. Burnout in the bottom of the piston indicates the engine with an incorrect ignition timing setting. The cause of erosion of the bottom of the piston usually is abnormal combustion (detonation). If these flaws are found, then you want to find the cause and correct, otherwise the possibility of serious damage. |
| 11. Corrosion of the piston in the form of pits indicating that the penetration into the combustion chamber (and into the crankcase) of the coolant. Here again, you want to find the cause and fix, otherwise possible failure of the repaired engine. |
 | 12. Measure the gap between the platform of the ring grooves and piston rings, which insert a new ring in the groove and pass between the probe and the ring groove. Check the gap in three or four locations along the length of the entire groove. |
| 13. Make sure that the ring corresponds to the groove, which will be installed as the sizes of various different grooves. If the backlash exceeds the limit, the piston must be replaced. |
| 14. Check the clearance between the piston and the cylinder, measuring the respective diameters. Make sure that the measurements are performed on a pair of mating parts. |
 | 15. Measure the diameter of the piston skirt. The clearance is defined as the difference between the diameters of the cylinder and piston skirt. If the clearance exceeds the limit, then the cylinder block to be boring, but the pistons and rings should be replaced by repair. (The clearance between the piston and the cylinder can also be measured, but with less accuracy using the probe, placed between the piston inserted into the cylinder, and the cylinder). |
| 16. Check the clearance between the piston pin and connecting rod, which is necessary to shake the piston and connecting rod in opposite directions. Tangible play point to increased clearance and the need to repair the connection. The piston assembly from the rod should be put into the repair to replace the piston pin and connecting rod to bore holes in the piston, and under repair sizes. |
| 17. If you need to remove the pistons from rods to replace the pistons or to eliminate backlash of the piston pin, you have to pass them to the workshop Car. At the same time it will be necessary to check the bending and twisting of the rods, which in the workshops have the necessary equipment. If you need to install new pistons and connecting rods, the pistons are detached from the connecting rods should not be. |
| 18. Check on rods cracks and other damage. Remove the cover at this stage of the connecting rod bearings, remove the bearings, clean the seating surfaces on the cover of the connecting rod bearings and connecting rods, and check for cracks, scratches and scuffing. After checking the reassemble rod, setting in place the bearings and tighten the nuts by hand. |
Old piston rings during disassembly of the engine always must be replaced. 
