Note. Broken valve springs and worn valve stem seals can be replaced without removing the cylinder head. You only need two special tools and a source of compressed air.
1. Remove the cylinder head cover (see Removal and installation of a cover of a head of cylinders).
2. Remove the spark plugs from the cylinders whose components need to be checked. If there is a need to replace the valve stem seals, remove all spark plugs.
3. After turning the crankshaft, bring the corresponding piston to the TDC position of the end of the compression stroke (see Bringing the piston of the first cylinder to the top dead center position (TDC)). When replacing valve stem seals, start with the first cylinder, then move from one to the next in ignition order (see Specifications).
4. Remove the rocker arm assembly with axles (see Removal, condition check and installation of rocker arm assembly).
5. Screw the adapter nozzle into the spark plug hole of the corresponding cylinder and connect the hose from the compressed air source to it.
Note. Special threaded sockets available with quick connection (see accompanying illustration) - ask in car service shops.
6. Supply air to the cylinder.
Attention! Under air pressure, the piston can move down, which will lead to a sudden turning of the crankshaft - do not leave the socket wrench on the bolt screwed into the shaft trunnion, with which the piston was brought to the TDC position.
7. Valves will be held in place by air pressure.
8. To prevent debris and other foreign objects from entering the engine, plug all openings in the block around the valves to be serviced with rags. Now, using a special tool, compress the spring of the valve to be serviced (see accompanying illustration). 9. Using needle-nosed pliers or a magnet, remove the crackers of the split lock from the grooves on the valve stem (see illustration for paragraph 8).
10. Remove the spring plate, shield, and spring from the valve stem, then remove the flinger cap from the valve guide.
Note. If it is not possible to fix the valve in the closed position with compressed air, then there is a leak, which is formed due to the presence of mechanical defects in the working chamfer of the plate or its seat. In this case, the cylinder head must be removed from the engine in order to carry out the appropriate reconditioning.
11. Attach a rubber band to the upper end of the valve stem, or wrap tape to prevent the valve from falling into the combustion chamber, then shut off the air supply to the cylinder.
12. Check the valve stem for signs of wear or mechanical damage. Rotating the valve inside the guide sleeve, evaluate the value of the radial play of its end, which determines the degree of straightness of the rod (bent valve to be replaced).
13. Move the valve up and down in the guide sleeve, trying to identify the jamming points, the presence of which indicates either deformation of the valve stem or damage to the sleeve - in any case, the head must be removed in order to perform the necessary reconditioning.
14. Re-inject air into the cylinder to secure the valve. Remove the rubber bandage/adhesive tape from the rod.
15. Lubricate the valve stem with clean engine oil and install a new oil seal.
Note. The valve stem seal springs are color-coded: white indicates the cap is for the intake valve, black indicates the exhaust valve.
16. Put the valve spring on the valve stem (end with a reduced pitch of turns to the head) with a plate.
17. Compress the spring with a special tool and carefully fill the cracks of the split lock into the groove. For temporary fixation of the crackers before releasing the tool, lubricate them from the inside with a thick lubricant (see accompanying illustration). 18. Watching for the correct fit of the crackers in the groove, release the spring compressor.
19. Shut off the air supply to the cylinder and unscrew the adapter from the spark plug hole.
20. Reinstall rocker assembly (see Removal, condition check and installation of rocker arm assembly).
21. Install the cylinder head cover (see Removal and installation of a cover of a head of cylinders).
22. Screw in the spark plugs and connect to them (in the required order) BB wires.
23. Start the engine and check for signs of oil leaks and unusual valve train noises.