Pistons — Removal and Installation (Mercedes-Benz Vario 814)

Removal

1. Remove the cylinder head.

2. Remove the tray.

3. Remove the connecting rod cap 5 (figure 3.16a).

4. Remove piston 1 together with connecting rod 4 from the cylinder block.

5. Mark the liners 7 together with the connecting rod caps 5 and connecting rods 4.

6. Remove piston pin 2 and remove connecting rod 4.

7. Check the connecting rod bolts 6.

8. Check the pistons and cylinder walls for wear. The piston dimensions are given in Table 3.5.

[Information copied from the website www.mercedesman.ru]

9. Check the piston rings, replace damaged ones.

10 Check and measure the dimensions of connecting rods 4 and 5 and connecting rod bearings 7.

Table 3.5. Piston dimensions

Parameters			Engines 904
Piston diameter, mm		BA label	101.781-101.790
		BC Label	101.790-101.799
Distance from the bottom of the piston to the axis of 1 piston pin	Standard	102 BA	64.36-64.40
		102BC
	Rem. size 1	102VA -0.3	64.06-64.10
		102BC -0.3
	Rem. size 2	102VA -0.6	63.76-63.80
		102BC -0.6
	Rem. size 3	102VA -0.9	63.46-63.50
		102BC -0.9
Piston protrusion above cylinder block, mm			0.28-0.50

Installation

11. Assemble piston 1 and connecting rod 4 together.

12. Lubricate piston 1 and install piston ring locks at 120° (arrow) (figure 3.166).

13. Install tension band 9 on the piston and tighten it to piston diameter 1.

14. Install the bearing shell 7 on the connecting rod 4 and the oil contact surface.

15. Insert piston 1 into the cylinder block so that the tension band touches the cylinder block. The arrow on the piston should point towards the front of the vehicle.



16. Push piston 1 into the cylinder block.

17. Tighten bolts 6 securing connecting rod cover 5.

18. Measure the piston protrusion.

19. Install the tray.

20. Install the cylinder head.