The transmission fluid is an important component of the vehicle’s transmission system. It lubricates the always moving parts of the transmission system. In automatic vehicles, it also acts as a coolant. In this article, we are going to look what happens when the transmission fluid leaks, what caused the leak and how to fix it.
If you’ve been to a mechanic, you have probably heard them mentioning transmission fluid. Transmission fluid is a green or red fluid (depending on the manufacturer) that lubricates the moving parts of the transmission system. In automatic vehicles, it also acts as a coolant for the transmission system.
There are several types of transmission fluids that al depend on the type of vehicle it is used on and the type of transmission in the car. Automatic transmission vehicles use regular fluid whereas manual has a variety of options.
For manual cars, they can use plain motor oil, hypoid gear oil or regular transmission fluid. If you have a manual car and are not sure which the best transmission fluid is for your vehicle, check the car owner’s manual.
What are the functions of transmission fluid?
The primary function of transmission fluid is to lubricate the always moving parts of the transmission system. This is because as you change and shift gears, there a lot of metallic components inside the transmission system that are moving as well. These components often get heated and produce heat and need a lubricant to reduce the amount of friction inside. While this in only the primary function, there are other functions transmission fluid does. They include:
- Act as a coolant to reduce the heat being generated by friction from the moving parts of the transmission system
- It cleans and protects the metallic components from wear and tear
- It conditions the engine gaskets
- It increases the rotational speed as there is smooth movement. This in turn increases the temperature range as less heat is emitted from the moving parts
All this functions are crucial to the operations of the transmission system. This is why when the transmission fluid starts to leak, you should get it fixed right away.
Is it dangerous driving with leaking transmission fluid?
While it is not dangerous to drive with leaking transmission fluid, it is important to know that the car will not run well. It is therefore recommended that you get the leak fixed immediately. But first, you have to know how to identify a transmission leak. If you spot a small puddle of reddish fluid underneath your vehicle, it indicates a transmission fluid leak. The fluid leaks when the car is parked on the same spot for a long period. As much as it is not dangerous to drive with leaking transmission fluid, it can be quite an expensive fix to repair the leak and replace the fluid.
Causes of transmission fluid leaks
The causes for transmission fluid leaks can range from minor issues to critical issues. As much as it is not dangerous to drive with leaking transmission fluid, it can be quite an expensive fix to repair the leak and replace the fluid.
If you take too much time before fixing a leak, the problem will get worse and end up costing a fortune. The following are the most common causes of transmission fluid leaks.
Seals are found in automatic transmission vehicles. Their main purpose is to sustain and hold hydraulic pressure as the transmission system works. Over time, the seals get worn out and crack due to the high temperatures being released by the transmission system.
It is one of the most common causes of transmission fluid leaks. If you discover a leak, always inspect the seals first as there is a high chance they might be the problem.
The gasket is the part where the cylinder head is connected. The gasket may get worn out over time and due to overuse. If this happens, gases in the cylinder leak out causing low compression.
Compression leaks can occur in two cylinders if the gasket fails between them. A cracked cylinder will leak gases and cause low compression in the engine. To identify a cracked cylinder, turn the engine on with the radiator cap open and check whether there are bubbles.
If there are bubbles, this means there is a leak coming from gases in the cylinder. Take the car to a professional mechanic for repair as delaying can cause serious and expensive damage.
Worn out drain plug
The drain plug or transmission pan experiences wear and tear over time. As you drive, a lot of debris and small hard rocks hit against the transmission pan. As this happens, the pan get worn out and eventually punctures. Other than that, the drain plug bolts loosen and the transmission fluid starts to leak out. It takes a long time to realize a small puncture leak than a huge puncture. It is important to ensure that the bolts are tightly closed to prevent leaks especially after a changing transmission fluid.
The valves are responsible for holding off the combustion pressure before releasing it to the exhaust. If the valves are damaged or leaky, the compression will leak causing low compression in the engine. To find a faulty valve, you will need a tester to check for gas leakages from the exhaust. Once you find the leaking valve, replace it.
Cracked fluid line
The transmission system is connected through a series of lines and pipes. The lines are made from steel or aluminum depending on the vehicle model and brand. Usually, the lines are made to be durable and last as long as the car but sometimes, they get damaged. The damage can be caused by debris and particles hitting against them while driving and heat produced by friction. If the lines crack, transmission fluid leaks through them. The lines need to be completely replaced when this happens.
Leaks in the Torque Converter
The torque converter is a component in the transmission system that propels transmission fluid in the system. If the pump that performs this function fails due to a crack on its body, the transmission fluid will leak. Unfortunately, this is not a simple fix and needs a mechanic and a huge check. Replacement is the only option.
How to fix leaking transmission fluid
For older cars, transmission fluid leaks are more common than in new cars. This is because the seals and other components of the transmission system are built to last about 75k miles. After this, they start to fail and wear out causing leaks. To fix the leaks, determine the size of the leak first.
For minor leaks, you can add stop leak solution that is sold in auto shops. Locate the leaking area and pour the stop-leak solution over the leak. The solution is very thick and will dry up and seal the leak. This also works for larger leaks. However, for large leaks, it is not a permanents solution as you will still have to take the car to a mechanic.
Leaking transmission fluid plug drain should be attended to immediately as many serious issues can arise in your car if left unattended for too long. Ensure that you practice the recommended maintenance habits and replace the oil filter every time you replace the oil. Such good practices will go a long way in preventing this leaking fluid problems.