Valve levers and hydraulic controls

Removal of air from the hydraulic regulator

Removing

1. Remove camshafts (see subsection 3.2.1.9).

2. Prepare 16 clean plastic bags and number them from 1 to 16. You can also get by with a 16-compartment box.


3. Remove the first valve drive lever, remove the hydraulic regulator from the hole in the cylinder head and put it in a bag along with the lever, observing the working position of these parts.

Attention! The hydraulic regulator must only be stored in the working position. When stored in a horizontal or upside down position, air will get inside the regulator, which must be removed before assembly following the recommendations set out in paragraphs 9 and 10 (see below).

4. Remove the spacers and guide discs from the ends of the valves, put these parts in a bag with the hydraulic regulator.

5. Repeat the steps according to paragraph 3 and remove the valve drive levers, hydraulic regulators, spacers and guide disks of the remaining valves. Do not confuse levers and hydraulic controls, otherwise these parts will be subject to increased wear.

Status check

1. Check the contact surface of the lever with the camshaft cam for signs of wear and damage on this surface. If the levers are worn, then the camshaft cams will also experience increased wear (see subsection 3.2.1.9). Replace levers if necessary.

2. Check for signs of excessive wear on the hydraulic controls and in the mating bores in the cylinder head. If the required measuring tool is available, the degree of wear can be determined by direct measurements. To do this, measure the inner diameter of the hydraulic regulator hole in the cylinder head and the external diameter of the hydraulic regulator. The gap in the hydraulic regulator is equal to the difference between these diameters. Compare the resulting clearance value with the standard specified in section (see subsection 3.2.1.1). Replace worn parts if necessary.

3. Check for signs of wear on the guide plates of the levers, replace if necessary.

Installation

1. Before assembly, the thickness of each spacer should be checked to determine suitability for further use. This operation is especially necessary if new valves and valve seats are to be installed, or if the valves have been reground. The procedure for checking the thickness of the gaskets is described in paragraphs. 2–5. If the cylinder head has not been repaired and measuring the thickness of the gaskets is impractical, then continue assembling, guided by see. item 8 and so on.




2. Install the actuator arm guide disc on the end of the valve from which the disc was removed (this is very important, see item 13). Attach a dial indicator to the cylinder head, bring the movable probe of the indicator leg into contact with the thrust surface of the guide disc in contact with the valve actuator lever. Set the indicator scale to zero.



3. Then carefully lift the indicator leg probe and rotate the indicator strictly parallel to the original position. Bring the indicator probe into contact with the end of the other valve that will be actuated by the actuator lever, i.e. the second valve from the same cylinder.

Attention! When turning, the indicator must move strictly parallel to the original position, otherwise the readings will be erroneous.

4. Read the indicator reading, which will be equal to the distance between the end of the valve stem and the thrust surface of the guide disc, which is affected by the valve actuator lever, record this reading. To ensure that the indicator head moves exactly parallel during measurement, rotate the indicator head back to its original position, where the indicator probe contacts the stop surface of the guide disk. The indicator reading when returning to its original position should be equal to zero. Repeat the above measurements for each pair of intake and exhaust valves for all cylinders. Write down the measurement results.

5. Based on these measurements, determine the appropriate spacer thickness for each valve pair. The thickness of the gasket must be exactly equal to the result of the measurement, however, a tolerance of±0.025 mm is specified by the manufacturer.

Attention! Spare parts are supplied with gaskets with a thickness of 2.800 to 3.200 mm in increments of 0.025 mm.

6. The thickness value is printed on the bottom surface of the gasket (for example, 2875 means 2.875 mm thick), However, it is highly advisable to measure the actual thickness of the gasket being replaced with a micrometer, as the thickness may decrease due to wear.


7. Install the spacers on the appropriate valve, making sure the labeled surface is facing down.



8. If shim thickness has not been measured, install guide discs and shims (indicated by arrows) onto the appropriate valves, making sure that the labeled gasket face is facing down.

9. Before installing hydraulic regulators, make sure that there is no air inside them. To do this, press the plunger of the regulator (the regulator must be in a vertical position, the plunger is facing up), the movement of the plunger should not be felt. If the plunger moves more than 1.0 mm, there is air inside the regulator. If air is found inside the regulator, or if a new regulator is being installed, the air must be removed by proceeding as follows.

Attention! On a running engine, air from the hydraulic regulators is not spontaneously removed. If the regulators are installed without removing the trapped air, then their normal operation will be disrupted and increased noise will be heard.

10. Prepare a small vessel, the dimensions of which are slightly larger than the dimensions of the hydraulic regulator, and a rod (e.g. piece of welding electrode), that goes into the hole in the regulator plunger. Fill the container with clean engine oil, the brand of which corresponds to that filled in the engine, immerse the hydraulic regulator in the container with oil, maintaining a vertical working position (plunger facing up). Insert a rod into the hole in the plunger and lightly push the regulator ball valve (see fig. Removal of air from the hydraulic regulator). While holding the bar in this position, slowly move the plunger up and down. In this case, air will begin to escape from the space under the ball valve. After the bubbles stop coming out of the upper part of the hydraulic regulator, release the plunger and remove the rod, after which the ball valve will close.

Attention! Keep the ball valve open while releasing the plunger.

11. Remove the hydraulic regulator from the vessel and check the stroke of the plunger (see item 9).

12. After removing air from the hydraulic regulators, install them in the cylinder head in their original places.

13. Install the valve drive levers in their original places, paying attention to the correct engagement of the levers with the hydraulic regulators and guide discs.

Attention! The ends of the levers that engage with the spacer and the guide sleeve vary in width. The end of the lever on the side of the spacer is slightly wider than on the side of the guide sleeve. If the lever does not fit this valve, the end of the lever will not fit into the slot on the end face of the guide sleeve.

14. Install camshafts (see subsection 3.2.1.9).