Modern tech engines are poorly presented without a good lubrication system. But also it is necessary, that oil has not got to cylinders.
What is a valve seal?
Oil valve caps (or glandsvalves) are designed to prevent excess oil from leaking from the engine. Like most parts in the engine, they are made of special rubber compound. Time passes, these parts age, which means they lose their effectiveness. This is characterized by a bundle. Old oil seals poorly hold excess oil, and the consumption of lubricant increases significantly. In addition to the high consumption of lubricating fluid, it can greatly harm the motor. Let's look at the signs of failure of these parts, as well as learn how to replace the valve stem seals.
Why are they needed in the engine?
In the cylinder head valves are locatedwho are involved in the work of ICE. The upper part of the part, or rather its leg, is constantly in contact with the camshaft. When it rotates, a suspension of oil is created in the cylinder head. The other part of the valve is located in the zone where it constantly contacts with the fuel mixture and exhaust gases. To work the camshaft was reliable and uninterrupted, you need a large amount of lubricant. But it should be borne in mind that the ingress of lubricant into the combustion chambers is unacceptable.
So the engineers came up with this detail. When the valve is in motion, the rubber gland removes the oil from the foot, while not passing it into the combustion chamber.
Where to find valve seals?
In the engine to find the valve stem seals easy andsimply. They are located directly on the valve, if the engine assembly. If the engine is disassembled, then you need to look for them in the cylinder head. The amount of these details is easy to figure out. There are as many as valves.
How does the gland work?
A modern gland is a rubber cap. For reliability, it is reinforced with a steel sleeve and spring. The spring allows you to more tightly press the edge of the cap to the working part of the valve.
Эффективность детали определяет не сама design. The material of which the stuffing box is made is important. If the cap is made of acrylate rubber or tamper, then you can talk about a good seal.
The engines of outdated models are equipped with unreinforced seals, which are made of fluoroplastic - efficiency achieved through a wider edge.
It is necessary to understand that the wear of oil scraper capsIt does not depend on the level and class of the car, as well as those technologies that are used in their production. And in various models of the WHA and Mercedes glands may have the same service life.
You need to know exactly which capsstand in the motor. After all, the replacement process is quite an expensive operation. This is primarily due to the fact that it is necessary to disassemble the engine. Also, automakers advise installing only original parts for a specific engine model.
Oil scraper caps - signs of wear
The crankshaft rotates by 500 when the engine is runningrpm at idle, and when driving - up to 4500 r / min. Every minute the valves go from 150 to 1200 cycles. Naturally, the glands have a large load. In addition, the cap is still highly affected by an aggressive chemical environment. Here oil and hot exhaust gases act on the stuffing box material.
Because of such loads, the material from whichthe softest part is made, it becomes harder. Then, the working edges of the part are erased. In this case, the replacement of oil scraper caps is to be carried out; the engine can also be washed or prevented.
However, do not think that the glands are necessarychange every year. Modern manufacturers have already established a culture of production of these parts. Replacement is required once every 100,000 km. But there are motors where replacement needs to be done more often.
What are the old oil scraps signswear? Here they can be seen even externally. Wear can be recognized by the gray smoke from the exhaust pipe. It can appear for a while only when the engine is started or when the motor is braked.
On parts like valve seals,signs of wear in the form of smoke are not the only factor. The second sign is an increased appetite for oil. In this case, leaks of lubricating fluid may not be observed at all. If we talk about, the flow rate will increase to 1 liter of oil per 1000 km. Also another sign is the salting and oiling of the electrodes on the candles.
How to replace the valve stem seals?
Many advise to carry out this operation in certified service stations, as the work requires disassembling the motor. You can carry out this operation without removing the cylinder head, you need only stock up on the necessary amount of patience.
Set of tools
For the work will need some tools.Usually requires a set of tools that is used in the repair of the motor. We need pliers and special tools that will compress the valve spring. Tweezers will be needed in order to get crackers. In addition to all this, you need a mandrel, which will be used for pressing the glands. Still need a hammer and tin solder rod. Bar dimensions should be no more than 8 cm in diameter.
We carry out the replacement
Removing the oil wiper caps providesthe following actions. First you need to dismantle the cylinder head cover. Then crank the crankshaft. It is necessary to turn it up until the mark on the camshaft sprocket coincides with the same mark on the bearing housing. Next, remove the bearing housing along with the camshaft. Now you can fix the sprocket and chain. Disconnect the wires from the spark plugs and turn out the candles.
In the next step, we press the spring well andremove the valve lever. We remove from under the locking plate and remove the spring. Turning the adjusting screw. In place of the screw is required to screw the tool that can compress the valve spring. In the hole, which was formed by removing the candle, insert our bar. This is required to keep the valve closed. Now we will free the crackers. To do this, it is usually necessary to squeeze the valve spring and tighten the spreader bolt. Remove the parts, remove the tool.
Now you can see the seals.If you do not know how to change the valve seals, you should use a collet clamp. This allows you to remove seals using light strikes of the striker. You should not use screwdrivers, pliers or any other similar tools for pressing out. So you can rip the sleeve.
A new part must be carefully put on the valve (andat the same time try not to damage the extreme part of it). Internal surfaces must be oiled. So it turns out to push the oil seal along the valve to the guide sleeve. Now it remains to gently knock and finally press the gland.
After successful pressing it is time to collect everything in reverse order. So you learned how to change the valve stem seals.
How to choose the glands?
Today there are practically no problems with spare parts. However, it is not necessary to exclude the situation when you have to trust not with the spare parts recommended by the manufacturer, but with those in stores.
If we talk about the choice of oil seals, thentheir main purpose is a seal for valve stems as well as valve bushings. These glands must protect the combustion chambers from oil. When oil seals are visible, signs of wear, it's time to attend to the acquisition of new ones.
You know how these elements work.As the use of these parts shows, it is this solution that allows to get good results. Thus, protection is preserved even when suddenly the valve stem is skewed.
New models of caps made of fluoride rubber or acrylate rubber are used on modern engines. However, no one anywhere said that they could not be used on older machines.
If the old engine to install newoil scraper rings, signs of wear will appear much later than the deadline, and the motor itself will greatly benefit from such a move. This is the best solution if the cap fits the valve for fit sizes.
It is also important to consider the inside profilegland. For example, Japanese engines have caps that have a lip inside. On the guide sleeve in this place the groove. You should not conduct experiments and put such details on smooth sleeves.
Long life caps provide installation of newballing on new engines. If the old motor can put new models of caps and nothing will happen, then if you put the old model of the gland on the new model of the internal combustion engine, anything can happen. It’s not even a matter of which valve seals for design features, but that the new power plants operate in extremely rigid conditions. Older models of glands simply will not withstand such loads. Therefore, their purchase is meaningless.
So, we figured out what are the wear valve caps.
