Leon Mk2
Piston, connecting rod, and casing: removing and installing |
1 - | Safety cotter pin |
2 - | Piston pin |
q | If movement is sluggish, heat the piston to 60 °C |
q | Remove and install with -T20019- |
3 - | Piston |
q | Mark the fitting position and correspondence with respective casing/cylinder |
q | The arrow on the piston head indicates the engine's turning direction (towards the camshaft side) |
q | Install with casing to fit rings |
q | Only install pistons of the same weight category (+ or - on the piston head) |
q | Only available as a replacement part together with the casing |
4 - | Piston rings |
q | Stagger the cuts by 120° |
q | Remove and install the compression rings using ring pliers |
q | Carefully remove and install by hand the 3 piece oil scraper rings |
q | The inscription “TOP” should must indicate the piston head |
q | Check the play between the ends of the rings → Fig. |
q | Check the coupling play between the rings and the grooves in the piston → Fig. |
5 - | Connecting rod |
q | Replacement part only available as a complete set (four rods) |
q | Mark correspondence to cylinder → Item |
q | Fitting position: The marks -B- must point towards the distribution |
q | Axial guidance by piston |
6 - | Connecting rod caps |
q | In the case of fractured or “cracked” connecting rods, the cap can only be fitted in one position and only on its corresponding connecting rod |
7 - | Connecting rod bolt, 20 Nm + 1/4 of turn (90°) |
q | Renew |
q | Lubricate the threads and the contact surface |
q | In order to measure radial play, tighten to 20 Nm, without retightening |
8 - | Engine block |
q | The surfaces where the casings will go must be clean and even |
q | Remove dirt and grime from the surfaces only by cleaning; do not use sandpaper, scraper or the like |
9 - | Half bearings |
q | Fit the centred half bearings |
q | Do not interchange the used half bearings |
q | Measure pre-tension → Fig. |
q | Measure radial play with Plastigage: New: 0.020...0.061 mm Wear limit: 0.091 mm When measuring radial play do not turn crankshaft |
10 - | Washer |
q | Renew |
q | To correct the casing's pre-tension |
11 - | Casing |
q | Observe the weight category (+ or - on the piston head) |
q | Only available as a replacement part together with the the piston |
q | Measure the pre-tension → Fig. |
Piston ring Dimensions in mm | New | Wear limit |
1st compression ring | 0.20...0.50 | 1.0 |
2nd compression ring | 0.20...0.50 | 1.0 |
Scraper ring | 0.40...1.40 | -- → Note |
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Piston ring Dimensions in mm | New | Wear limit |
1st compression ring | 0.04...0.08 | 0.15 |
2nd compression ring | 0.04...0.08 | 0.15 |
Scraper ring | not measured |
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Note!
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