If it is possible to use a source of compressed air with a pressure of 7-10 kgf/cm², then the oil seals can be replaced without removing the cylinder head from the engine. If there is no source of compressed air, you will have to remove the cylinder head, since on this engine it is impossible to fix the valves with mechanical devices inserted into the spark plug hole.
Fig. 5.6. Tools for removing valve springs: 1 – spring compression device; 2 – device for supplying air to the spark plug hole
You will need: all the tools needed to remove the cylinder head cover (see " "Replacing camshafts"), as well as tweezers (or a magnetized screwdriver) for removing crackers from the valve spring plates, device 1 (Fig. 5.6) for compressing the valve springs, device 2 for feeding air into the spark plug hole (can be made from a faulty spark plug)…
…tick-borne…
...or an inertial valve stem seal puller. The puller shown has a mandrel on the other end for pressing the caps on. If you don't have such a puller, you'll need pliers to remove the caps and a mandrel of the appropriate diameter to press them onto the valve guides.
1. Disconnect the wire from the negative terminal of the battery.
2. Remove all spark plugs (see "Replacement and maintenance of spark plugs").
3. Set the piston of the 1st cylinder to TDC (see "Setting the piston of the first cylinder to the TDC position of the compression stroke"). This position corresponds to the BDC of the pistons of the 2nd and 3rd cylinders.
Note: If the piston is not set to BDC, when compressed air is supplied to the cylinder, the engine crankshaft will turn and the vehicle may move (with the gear engaged).
4. Remove the cylinder head cover (see "Replacing the cylinder head cover gasket").
5. Remove the timing belt (see "Replacing the timing belt").
6. Remove the camshafts (see "Replacing camshafts").
Fig. 5.7. Valve drive parts: 1 – pusher; 2 – rusk; 3 – spring plate; 4 – spring; 5 – oil seal
7. Remove the tappets 1 (Fig. 5.7) of the valves of the 2nd cylinder.
8. Install the valve spring removal tools on the 2nd engine cylinder as shown in Fig. 5.6.
9. Supply compressed air at a pressure of 7–10 kgf/cm² to the spark plug hole of the 2nd cylinder.
10. Compress spring 4 (see Fig. 5.7) of one of the valves with the device and remove two crackers 2 from plate 3 of the spring using tweezers or a magnetized screwdriver. Then remove the device.
Caution! After removing the crackers, the valve is held in the upper position only by air pressure. Do not turn off the pressure until the replacement of the oil seal and installation of all parts is complete, otherwise the valve will fall into the cylinder. To remove it, you will need to remove the cylinder head.
11. Remove spring plate 3 and spring 4.
Note: If you are removing retainers and springs from several valves at the same time, the removed parts should be installed on the valves from which they were removed.
12. Press the valve stem seal 5 off the valve guide sleeve. To do this, install the collet of the inertial valve stem seal puller on the seal and sharply hit the collet sleeve with the striker. Then, just as sharply hit the handle of the device with the striker, thereby pressing the seal off the sleeve.
13. If there is no inertial cap puller, remove the cap with a special pliers-type puller or pliers, applying force strictly upwards and without turning the cap, so as not to damage the valve guide sleeve.
Warning! Do not remove the cap by prying it from both sides with screwdrivers. The guide bushing on which the cap is placed is made of metal ceramics, and its edge easily breaks off.
14. Before installing new valve stem seals, we recommend removing the springs from them, otherwise the caps can be damaged when they pass through the grooves for the crackers on the valves. If the new caps come with a plastic installation sleeve, you can leave the springs on. In this case, put the sleeve on the valve stem.
Note: Original intake valve stem seals are green, exhaust valve stem seals are brown.
15. Lubricate the inner surface of the valve stem seal with engine oil and slide the seal along the valve stem to the guide sleeve.
16. Install the mandrel for pressing the cap. Press the cap in with light blows of the striker on the mandrel until it stops. If you do not have a special device, you can select a cylindrical mandrel of a suitable diameter and press the cap through it with light blows of a hammer on the mandrel.
Note: You can use the long head from the tool kit as a mandrel. In this case, you need to choose a head with 12 faces and a chamfer inside the hole so that the head contacts the cap along a solid circle.
17. Remove the guide sleeve from the valve stem or place the spring on the cap if it was removed.
18. Install the spring and valve plate in the reverse order of removal. Install the crackers using the device so that they fit into the grooves of the valve stem. After installing the crackers, hit the end of the valve with a hammer through a metal rod so that the crackers fit into place.
Warning! If the crimped valve crackers are not secured, the "loose" valve will fall into the cylinder when the engine is started, which will cause serious engine failure.
19. Similarly, replace the oil seals of the remaining three valves of the 2nd cylinder and four valves of the 3rd cylinder.
20. Turn the crankshaft half a turn so that the pistons of the 1st and 4th cylinders are at BDC, and replace the oil seals of the remaining valves.
21. Install the removed parts in the reverse order of removal. After installing the camshafts and timing belt, check and, if necessary, adjust the valve clearances (see "Adjusting valve clearances").