Skoda Workshop Service and Repair Manuals

Disassembling and assembling piston and conrod 1 -  Piston rings –  Offset joint 120° –  use piston ring pliers for removing and installing –  marking “TOP” faces piston crown –  inspect gap clearance → Fig. –  inspect end clearance → Fig. 2 -  Piston –  check → Fig. –  mark installation position and matching cylinder –  arrow on piston crown faces towards the belt pulley side –  use piston ring tensioning strap for installing –  Ø Pistons: 76,485 3 -  Piston pin –  if stiff, heat piston to 60°C –  removing and installing with -MP 1-205- 4 -  Circlip 5 -  Conrod –  replace as a set only –  mark matching cylinder -A- –  Fitting position: Markings -B- point towards the belt pulley side –  Clean head contact surfaces with compressed air –  located axially by pistons 6 -  Bearing shell –  Check fitting position –  do not mix up used bearing shells –  ensure tightly located in retaining lugs, so that the preload can be measured → Fig. 7 -  Cylinder block –  inspect cylinder bore → Fig. –  Ø Cylinder: 76,51 8 -  Conrod cap –  Check fitting position –  Clean head contact surfaces with compressed air 9 -  Conrod bolt, 30 Nm + torque a further 1/4 turn (90°) –  replace

Inspecting piston ring gap clearance –  Insert ring at right angles from above down into lower cylinder opening, about 15 mm away from edge of cylinder.

Piston ring dimensions in mm	New	Wear limit
1. Compression ring	0,20 ... 0,50	1,0
2. Compression ring	0,40 ... 0,70	1,0
Oil scraper ring 1-part 3-part	0,25 ... 50 0,40 ... 1,40	1,0 --- → Note

1)  no specification possible for wear limit

Inspect piston ring end clearance Clean ring groove before inspecting.

Piston ring dimensions in mm	New	Wear limit
1. Compression ring	0,04 ... 0,08	0,15
2. Compression ring	0,04 ... 0,08	0,15
Oil scraper ring 1-part	0,04 ... 0,08	0,15
3 part	cannot be measured

Inspecting pistons Special tools and workshop equipment required t  External micrometer 75 ... 100 mm –  Measure about 10 mm from the lower edge and offset 90° to piston pin axis. Deviation from specified dimension max. 0.04 mm.

Inspecting cylinder bore Special tools and workshop equipment required t  Internal precision measuring instrument 50 to 100 mm –  Measure at 3 points crosswise in a transverse direction -A- and lengthwise -B-. Variations compared to nominal dimension max. 0.08 mm   Note Do not measure the cylinder bore if the cylinder block is fixed to the assembly stand with the engine mount -MP 1-202-, as this may result in incorrect measurements.

Measure preload of bearing shells Special tools and workshop equipment required t  Caliper gauge The preload of the bearing shell can be calculated as follows:

-	Dimension -a- of bearing shell diameter of conrod -b-
=	Preload

Minimum dimension: 1.5 mm If the preload is not reached: –  Replace bearing shell.