Replacement of the valve bushing: mechanism design
Replacement of the valve guide sleeves is necessaryTo carry out at repair of a head of the block of cylinders, and also at excessive deterioration of elements. Domestic cars have a significant advantage - they can be repaired independently, having at hand a minimum number of tools and devices.
Also in stores there is a large selection of spareparts of different manufacturers, so they never have problems with them. However, when adjusting the valves on the front-wheel drive vehicles, washers are required, they are not always available on the market. But the guide bushings are relatively simple to change. This procedure will ensure the normal operation of the engine.
Why you need a bushing
In order to ensure stable and uninterrupted operation of the internal combustion engine, the head of the structural unit is used. It contains the following elements:
- Valve guide sleeves.
- Plates and springs of valves.
- Crackers for fixing the elements.
- Oil seals to prevent oil from entering the combustion chambers.
When replacing the valve guide sleeves VAZ-2109you need to ensure maximum purity. All work should be carried out only on a workbench, before installation it is necessary to clean all the elements from contamination. Otherwise, dust particles will enter the combustion chamber and damage the surface of the sleeves.
Valves are installed in holes, throughwhich passes the fuel mixture and exhaust gases. The more accurate the valve system will work, the higher the engine power, its torque. If the guide is a bit deformed, it will cause the piston leg to not move normally - it will be hampered by the frictional force. Because of this, the efficiency of the entire mechanism is reduced several times. The probability of breaking the timing belt increases.
Valve System Design
On each valve there are plates - working partsdisk form. They are as close as possible to the nest. To ensure the most dense connection, it will be necessary to do a lapping during the repair. For this, special abrasive pastes are used. The second part of the valve is a rod with slits at the end. With its help, the forward and backward movement to the plate is transmitted. Thanks to this, the opening in the head of the unit opens and closes in a timely manner.
To ensure the movement of the valve strictly along the axissleeves are used. The design is such that the valve stem can not move sideways - only up or down. There are no gaps between the inner part of the bushing and the stem, therefore it can not pass through the engine oil into the combustion chamber. Although oil seals are used for this purpose. But over time, it is necessary to replace the guide valves, since under the influence of frictional force they are still destroyed.
When it is necessary to change the bushings
Be sure to make sure that the bushings are faulty. Analogous signs can also occur when the seals fail. When do I need to change the guides on the valves?
- If there is an engine oil in the combustion chambers. At the same time, from the exhaust pipe there is a gray smoke, the oil consumption increases.
- If there are knocks and other extraneous sounds coming from the side of the cylinder head.
- If the head of the unit is being repaired, be sure to install new guides.
- At replacement of all valves in ГБЦ after damages (at breakage of a belt газораспределительного the mechanism).
- When carrying out the overhaul of the head of the unit.
Preparation for repair
Maximum care must be taken to repairhead and timing mechanisms. It is necessary to have several special tools, a set of keys will clearly not be enough. Replacement of the valve guide sleeves VAZ-2106 is carried out exactly the same as on any other model. The design is different, but insignificant. The master will need this tool:
- The mandrel for pressing the guides out ofnumber of seats. It can be manufactured on a lathe or purchased in a shop. Factory products have a handle and a working part, which is a metal rod with a diameter slightly smaller than that of the sleeve. At the end, the part is thinner - it freely penetrates into the inner hole of the valve bushing.
- Special sweeps with dimensions 8,022 ..8,040 (for intake valves) and 8,029..8,047 (for exhaust valves). By means of these devices, which are elongated drills, it is possible to increase the diameter of the holes in the head of the block for the installation of the guides to the desired size.
All work should preferably be done with the head removed. Be sure to remove the valves, seals, camshaft and other elements.
In advance, clean all contaminants from the head of the unit. Put the new guides in the freezer a couple of days before the repair. The algorithm for performing the work is as follows:
- Insert the mandrel from the inside, apply punches with a hammer to knock out the old bushings. Do this as neatly as possible so as not to damage the cylinder head elements. Remove all guides.
- Clean the seats for the installation of new bushings. Use a solvent and a brush for this. After all, blow out with compressed air.
- Warm the block head on the electric stove to 100 degrees. During this process, the planting holes will expand, it will be easier to install the bushings.
- Install the locking rings on the bushings.
- Insert the guides into the mounting holes, hammer them with the mandrel until it stops.
Completion of work
Before installing the valves, modifyinternal holes in the sleeves. To do this, allow the head of the unit to cool completely. Try to install the valves - if they do not enter, then use the sweep to enlarge the hole. First use the smallest size. Be sure to try the valve after each pass.
You need to achieve maximum landing densityvalve in the bushing. When replacing the guide sleeves of VAZ-2112 valves, always mark the position of the inlet and outlet openings. The inlet sleeves are shorter than the outlet ones, so it is impossible to confuse them during installation.