GA engines
1. Remove the cylinder head cover.
2. Remove the camshaft.
3. Remove valve spring (see section «cylinder head»).
4. Remove the old oil seal using an appropriate tool.
The piston of this cylinder must be set to TDC to prevent the valve from dropping.
5. Apply engine oil to the new oil seal and press it in using a suitable mandrel.
SR engine
1. Disconnect the throttle cable.
2. Remove the cylinder head cover and oil separator.
3. Remove camshafts and sprockets (see section «Timing gear drive»),
4. Turn out spark plugs.
5. Apply compressed air at a pressure of about 490 kPa through the spark plug hole (5 kgf/cm2).
6. Remove the valve actuator lever, lever guide, and washer.
7. Remove the valve spring using the special tool.
The piston of this cylinder must be set to TDC to prevent the valve from dropping.
8. Remove the old oil seal using pliers.
9. Coat the new oil seal with engine oil and press it in with a suitable mandrel.
CD engines
1. Remove both toothed belts.
2. Remove pulleys and camshaft covers.
3. Remove the camshaft bearing caps by loosening the nuts from the center outwards in two or three steps.
4. Remove a camshaft with epiploons.
5. Remove the valve lifters, marking them so as not to be confused during installation.
6. Replace the oil seals as follows:
- a) Set the piston of the 1st cylinder to TDC.
- b) Remove the valve springs and the old oil seals of the 1st and 4th cylinders. The spring seats do not need to be removed.
- With) Press on new oil seals for the 1st and 4th cylinders. Install springs (the narrow pitch side must face the cylinder head).
- d) Install the spring retainers on the intake valves and the rotators on the exhaust valves.
- e) Set the piston of the 2nd cylinder to TDC.
- f) Replace oil seals of the 2nd and 3rd cylinders in the same way as points b) and with).
- g) Install the valve lifters in their original positions.