Replacing the valve stem seals and lifters

in #replacing8 years ago (edited)

Valve seals

Valve seals otherwise they are magnified – valve seals. Belong to detail, having a very small size, but after their failure engine operation is not possible. Find valve seals in the engine very easily. They are located on the valve in the cylinder head of the engine. Their number is the same as valves.
These little parts to stop the flow of lubricant from one section to another engine, where lubricant is not needed. And the valves are at the top with the rest of the parts, which should be well lubricated and the seals do not allow oil to leak into the combustion chamber of the engine.

The shaft seal

When the knees, shaft gives a tremendous load on the valve seals, in addition to them constantly the effect of chemical aggression. It is possible to carry the oil itself and the engine exhaust. Due to constant exposure to the seals, soft part of them hardens, and all working edges are getting a little blurry. In this case, the valve seals need to be replaced and it is desirable to carry out prevention and flushed the engine. Ideally you want to replace seals every one hundred thousand kilometers, but there are such engines, which often have to be replaced.
Visually determine wear on oil seals is possible on a bluish color exhaust. He appears only momentarily when you start the ignition or when the engine stops.

If you do not change oil seals

When valve seals fail, then the engine tries to pick up the oil. At first, it can be seen in the form of smoke when starting the engine, unstable work it, and then further refuse to wear candles, and increases the amount of oil on the burn.
If the oil starts to get into the combustion chamber, it is bad for the functioning of the valves themselves, because their core begins to collect carbon deposits, and the same goes for the piston head, which deteriorates the heat sink parts and leads to overheating and wear.

How to change the seals

For replacement, we need a tool :
1) pliers.
2) the special tool that compresses the valve spring.
3) tweezers (need to get crackers).
4) the mandrel with the help of which you can extrude seals.
5) the hammer.
6) solder a piece of tin (not more than 8 cm in diameter).

Begin replacement

The first thing to do is to remove the cover from the cylinder head. After cranking the knee shaft. Should be rotated until they connect the marks on the sprocket shaft before races such as typically the bearing. After you fix the chain and sprocket and disconnect wires from candles, and then remove them. Press the spring and remove the lever of the valve actuator. Gone from locking plate and pick up the spring. Unscrew the adjusting screw, and tighten it a special tool that will help compress the valve spring.
In the hole from the spark plug tin rod to close the valve, then take out the crackers. What would it do to compress the valve spring and install the bolt rassuharivatel. Finish with removal of parts and collect tools.
Now you can visually see the seals. To replace seals you need a collet. He will help us by not strikes of the firing pin to remove valve seals. In any case, do not use for pressing with a screwdriver and other necessary tools. You can strut bushing.
New seal gently put on the valve, grease the inner surface and only a little Bang and the gland is pressed. At the end of the pressing need to collect everything in reverse order.

Lifters engine

These are devices that automatically adjust the clearances at the valve. They appeared in the form of replacing a less efficient mechanical regulators. Let's take a simple valve of the engine such as the VAZ 2107, it does not have the tappet and is therefore often have to adjust. Basically, every ten thousand kilometers.
The work of the tappet is based on the principle, not the compressibility of the oil filling during operation of the engine the entire inner part of the tappet and its plunger moves during the occurrence of clearance in the valve drive, provide permanent contact of the roller rocker arms and valve actuator with the Cam of the camshaft.

Where to find hydraulic lifters

Are the lifters between the valve stem and the fist races before the shaft. They are like small piston, because for them there is a place in the head.
When you need to change the tappet
During use, and non-compliance with conditions of use and the recommendations of the manufacturer, there is a wear of this details ahead of time.
The engine makes a distinctive sound. This sound indicates that the tappet is broken and needs to be replaced.

Reasons:

1) the wear of the working surface of the check valve and plunger pairs.
2) clogging of the flow channels of the oil in the engine.
3) formation of shock loads as a result of filling or partial filling of the tappet with oil.

If you long to change

If you strongly constricted valve, the gap is either small or do not exist because of this incomplete closure reduces the compression and this leads to loss of power, burnt valve discs and ignition of the fuel mixture in the manifold.
And with large gaps appear to impact loads, they are contacted with details of timing and lower their resource. In addition to everything else going wrong with filling a fresh charge, and this leads to a torque reduction of engine power.

Replacement tappet

To replace the tappet, cylinder head can not be removed. It will be enough to remove the camshaft cap. A head gasket then necessary to replace with a new one, because the body of the camshaft and GB attached to some bolts and re-twist bolts legacy head gasket may not provide tightness of connection.

What to do:

1) open the body of the camshaft.
2) remove the pressure lever and the key on the valve stem.
3) remove from the socket GB the tappet.
4) to lubricate the tappet and the newest socket in cylinder head with engine oil and insert the tappet in the slot.
5) similarly, replace all the remaining lifters.
6) insert the top of the cylinders and the details of timing in the reverse order.

So it is very easy to replace, you can replace the valve seals and the tappet engine without resorting to professional help. 


  #autorepair   #replacingtheseals 

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Thanks, Your article helped me

great article, very helpful

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