Valve stem seals are the only valves in the car engine that are designed with a leak or some are designed with meter oil, which is past the seal and fixed metering rate. Therefore the term ‘seals’ in these valves is a misnomer. They are designed with a leak because of the lubrication needs at the valve train, which is situated right below the seal. A valve stem seal also acts as guide for preventing wear and scuffing; it limits the quantity of oil from entering inside the combustion chamber. If you know how to replace valve stem seals then it can save time and you won’t have to rush to a mechanic.
If there is excessive oil, then it can affect the engine emissions and the performance as well. If there is sufficient oil, then it will increase the durability. The basic function of the valve stem seal is of a wiper. The sealant will wipe off the oil from the valve stem as it starts oscillating up and down inside the valve guide. However, due to the requirement of lubrication beneath the seal, the amount of oil that is being wiped from the valve stem should be controlled. There are many things that are considered when determining the quantity of oil, which is metered from the seal at a set time.
Except for the sealing, many other things are considered in the valve stem seal designing. The operating system of the seal is responsible for determining the remaining design of the seal. The operating temperature, geometry of the valve train, oil type, spring design of valve and method of assembly have a great impact on the design and real function of the valve stem seal inside the engine.
Over the time, the leaks in the seals increase causing huge amount of oil to flow out than required. In this situation, it is best to replace the valve stem seal. Here are some simple steps on how to replace valve stem seal.
Things Required:
- Wrench set
- Socket set
- Hammer
- Valve spring tool
- Pliers
- Screwdriver
- Air compressor
- Compression gauge
- Old spark plug
- Air chuck fitting
Steps:
- The first step will be to disassemble the engine from below, so that you have access to the valve spring properly. After that, you will have to remove the cylinder head cover, push rods and the rocker arms. Later you will have to remove the spark plugs as well.
- The next step for replacing the valve stem seal will be turning the air compressor and regulating the air to 60-90 psi. You will have to turn the crankshaft until the cylinder you want to replace gets the valve seal right on the top center. Remember to screw the compression gauge hose inside the spark plug hole, and fix the air compressor hose, so that your cylinder is well pressurized. Later the valves will stay close to each other as the air pressure starts building up.
- For replacing the valve stem seal you will have to use the valve spring tool. You must compress the spring on the valve and take out the valve keepers with the help of the magnet. These valve keepers will be stuck inside the valve spring retainer and with the help of a hammer or your hand, you can loosen it. Take some towels and pack it around that area so that you do not lose the keepers from the engine, and then you can remove the springs.
- Now the last step for replacing the valve stem seal will be to remove the old valve seal with the help of a screwdriver or pliers and replace the valve stem seal. Now you must reverse the entire process for reassembling the engine. Always remember that you must use a magnet to install the keepers and when you remove the valve spring compressor tap the top gently with a hammer for seating the keepers.
How to replace valve stem seals without removing the heads
- In this process, you will have to remove the old sparks first and break the ceramic area and take out the electrode. You will have to weld the threaded part on the air chuck fitting, ensuring that it is good bead so that air is not able to escape through it.
- The next step for replacing the valve stem seal without heads will be removing the spark plug from the cylinder and then replacing the plug with air chuck plug. Now you can put the air hose in fitting and this will be able to hold the outtake and intake of the valves when you take out the keepers and spring.
Tips and Warnings:
- Always remember that when you are replacing the valve stem seals you must have enough time then only the repair will go smoother. You will have to use the service manual for the torque specs when you are reassembling all the engine parts.
- Make sure that you clean all the old gaskets during the process of disassembly and then only the process of assembly will go smoother.
- When replacing the valve stem seals remember to wear safety glasses, since you will be working with compressed springs and tiny parts in the engine.
You will also need a clothespin, because if your air compressor stops working or you need to shut it down due to any reason, you can clip the clothespin on the valve and keep it from dropping inside the engine. If the valve drops inside the engine then you will have to take out the cylinder head for repairing it.
Related Tags: valve stem seals, replacing valve stem seals, how to replace valve seals, valve stem compressor, how to change valve stem seals, how to replace valve stem seals, how to remove valve stem seals, how to replace valve stem seal
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