Genuine Volvo S70 Piston

Volvo S70 Piston Parts and Q&A

• Piston
  272151
  Q: What steps should be taken before refitting the piston and connecting rod assemblies on Volvo S70?

  A:

  Before refitting the piston and connecting rod assemblies, be sure to make certain the cylinder bores are clean, and the top edges of each cylinder are chamfered, and the Crankshaft and intermediate section are in place. Remove the big end bearing cap within the No 1 cylinder connecting rod, taking note of any marks made during removal, Clean the bearing recesses using a lint free cloth, taking care to make sure new big end bearing cap retaining bolts are available. Clean back of new top bearing shell and fit it to No 1 connecting rod, then fit other shell of big end cap to the big end bearing, making sure that the tabs fit to the notches. Set Piston Ring gaps properly, lubricate piston and rings with clean engine oil and attach piston ring compressor and leave the skirt out slightly to direct piston into cylinder bore and compresses the rings flush with the piston. Rotate the crankshaft till the No 1 big end journal reaches Bottom Dead Centre and apply engine oil to the cylinder walls. Cap the No 1 piston/connecting rod assembly so that arrow on the piston crown aligns at the timing belt end and carefully insert the piston/connecting rod assembly into the cylinder bore and rest the ring compressor on the engine block. Tap the top edge of the ring compressor to make sure it is in contact with the block, then tap on the piston gently by a wooden hammer handle, while guiding the connecting rod big-end onto the crankpin, always keeping the pressure on the ring compressor to stop the rings popping out. If resistance is felt, stop immediately to find and work out the problem, without forcing the piston. Make sure the bearing surfaces are clean and spread a uniform amount of clean engine oil, perhaps shoving the piston back a bit to reveal the bearing surface. Slide the connecting rod back on the big end journal, re-install the bearing cap, lubricate and tighten the bolt threads in 2 stages to the given torque. Repeat process for the rest of the assemblies, the backs of the bearing shells and recesses must be kept clean, the correct piston/rod assembly for each cylinder must be certain, the arrow on the piston crown must face the cam shaft drivebelt end and the cylinder bores and bearing surfaces must be lubricated before the caps are fitted. After installation, turn the crankshaft by hand to check to see if there is any binding.
• Piston
  272914
  Q: How to remove the cylinder head, oil pump, and flywheel/driveplate while ensuring proper reassembly of the engine components on Piston on Volvo S70?

  A:

  To remove cylinder head and oil pump and flywheel/driveplate, first remove sump and intermediate section. Check for a heavy wear ridge inside the tops of the bores as this may have to be removed before piston extraction though significant damage is likely to require rebore and new pistons/rings. Make sure to get identification marks on each connecting rod and cap, adding them if you have to, to keep in the proper position for reassembly. Remove the connecting rod bolts, have them tap the cap with a soft hammer to loosen it and remove the cap and lower bearing shell, remembering to get new bolts to re-mount it. Push the connecting rod and the piston out the bore, picking up any loose bearing shell. Refit the cap properly and do not confuse components, and look for an arrow on the top of the piston pointing towards the timing belt end, if not, mark a direction. Without turning the crankshaft around, do the same for the other rods and pistons. Clean the piston/connecting rod assemblies and remove the original Piston Rings, using feeler blades to keep from dropping the rings into grooves. Scrape carbon from the piston tops and the grooves in the rings, using an old ring to scour the grooves of the rings without damaging them. After cleaning with an appropriate solvent, be sure oil return holes are clear. If there is no damage to pistons and bores, original pistons can be reused, but new piston rings are a must. Inspect each piston for cracks, scoring or burns as these can mean that there is overheating or abnormal combustion and can require a thorough check of the cooling and lubrication systems. Corrosion implies a leakage of coolant and needs to be rectified. Inspect connecting rods for any damage (make sure they are not bent); even this is a job for specialists. To disconnect (separate) pistons and connecting rods, take off a circlip and push out a gudgeon pin. Measure diameters of pistons with a micrometer and compare it with specifications because if one is out of tolerance, then all of them need to be replaced. Ring to groove clearance using a feeler blade, ensuring that correct ring sizes are used; if clearance is off then the pistons will have to be renewed. Check gudgeon pin fit in connecting rod bush and piston - replace if necessary. Gather any new parts you will need, making sure that new pistons are supplied with gudgeon pins and circlips. Oil the gudgeon pin and reassemble the connecting rod and piston in the appropriate way, and position the gudgeon pin in place using the circlip, opening downwards and repeat with the other pistons.