Contents: Removal ↡ Installation ↡
Worn oil seals can cause increased oil consumption. The seals can be removed with the cylinder head installed. However, this requires compressed air and a lever ejector with a support device, such as Mercedes-11 589 015900, 11 589 186 186 100 and 11 589 256 300. If there is no special tool, then the cylinder head must be removed.
Below is a description of how to replace the oil seals for a 4-cylinder engine, and for a 6-cylinder engine, follow the instructions below using the appropriate tool.
Removal
Attention! If the valve control parts are to be used again, they must be mounted in the same places. To avoid mixing up the parts, make a special panel for their storage.
1. Remove the camshafts.
2. Remove the spark plugs.
3. Remove the protective covering from the engine wires on the front body wall.
4. Screw the support bridge (2) with the movable part (7) to bearings 1 and 5 of the camshaft or later to bearings 6 and 10 with a torque of 20 Nm.
5. Turn the piston of the corresponding cylinder to TDC using a wrench with a socket. 4-cylinder engine: when the belt pulley is in TDC position, pistons 1 and 4 are in TDC. When the 180-degree mark of the belt pulley coincides with the base mark, pistons of cylinders 1 and 6 are in TDC. 6-cylinder engine: when the belt pulley is in TDC position, pistons of cylinders 1 and 6 are also in TDC. When the 120-degree mark of the belt pulley coincides, pistons of cylinders 2 and 5 are in TDC; at the 240-degree mark - pistons of cylinders 3 and 4.
Caution: When turning the crankshaft, lift the control chain high to prevent it from jamming.
6. Attach the lever pusher.
7. Pull out the plate pusher (3) with a rubber suction cup (diameter 30 mm), for example, HAZET 735-2.
Caution! Do not use a magnetic siphon for this, as the sliding surface of the disc tappet will become magnetized and subsequently tiny metal shavings will be deposited on it, which will damage the tappet and cams.
8. Lock the crankshaft. To do this, set the first gear and apply the parking brake.
9. Set the cylinder combustion chamber to an excess pressure of at least 6 bar. To do this, screw the connecting hose (4) of the cylinder leak tester into the spark plug hole. If there is no leak tester, you can make a suitable hose using an old spark plug.
10. Bite off the ground electrode of the old spark plug (1). Break off the ceramic insulator (2) with a screwdriver, and also break off the middle electrode (3) by rocking it back and forth and remove it. Push it out with a punch (about 3 mm) the remains of the middle electrode with the glass mass (4) and the connecting pin (5). In this case, clamp the spark plug in a vice or use a suitable screw-cutting machine.
Caution: Do not damage the spark plug threads to avoid damaging the threads of the cylinder head hole.
11. Screw the spark plug into the appropriate cylinder, connect it to the booster air hose and set the cylinder to an excess pressure of at least 6 bar.
12. Install the lever pusher (9) with the pressure part (5) on the valve spring plate. Position the pressure part and the movable part parallel to each other. Secure the movable part with the bolt (8).
13. Compress the valve spring.
Caution! Do not compress the valve spring without compressed air, otherwise the valves and pistons may be damaged.
14. Remove the valve stem parts (14) from the valve stem using tweezers (6) or a magnetic siphon.
15. Remove the valve spring plate (15) and valve spring (17).
16. Remove the valve stem seal (86) from the valve stem using special pliers, such as HAZET 791-6.
Caution: Do not damage the valve stem or guide.
17. Remove the valve spring plate (15) and valve spring (17).
18. If necessary, remove burrs from the valve stem groove with fine-grit emery cloth.
19. Check the valve guides for wear in the area where they contact the valve stem seals. Replace the valve guides (work for repair shops).
Installation
1. Replace bent parts of the stem, valves and spring plate.
2. Valve guides that are out of alignment with the valve stem seal retaining groove must be replaced (work for the workshop).
3. Place the protective sleeve (2) onto the valve stem.
4. Lubricate the oil deflector cap (86) with oil and fit it by hand using a mounting mandrel.
Attention! The mounting mandrel is included in the repair kit. If the attachment is made without the mounting mandrel, the sealing chamfer of the oil deflector cap is damaged.
5. Install and secure the valve springs and valve spring retainer.
6. Insert the valve stem parts, release the valve springs.
7. Install the plate plunger.
8. Replace the oil seal.
9. Unscrew the spark plugs.
10. Install the camshafts.
11. Secure the engine wiring harness cover to the front body wall.