Clutch Won't Bleed - Why? Here Are Some Solutions

The three pedals (in manual transmission) in most cars are the most used component. The gas pedals, brake pedals, and clutch pedals are what makes our cars move and stop. Maintaining these components periodically is a mandatory part of having an automobile. However, in this article, we will be focusing on the clutch.

Drivers that love to use manual transmission cars can have trouble maintaining their transmission. Luckily for you, we have various solutions so that you can still enjoy the thrill of manually shifting the gears in your car.

What is a Clutch?

The clutch is what makes your transmission detach from the engine - so you could freely move between the gears. The basic component of the clutch is the Master Cylinder and the Slave Cylinder. The clutch is connected to the pressure plate sitting between the engine and the transmission.

When the clutch pedal is pressed, the Master Cylinder will be compressed creating pressure for the slave cylinder which will signal the pressure plate to loosen up, removing the connection from the crankshaft of the engine, and then you can shift your transmission into another gear (up and down).

Without the clutch, the gears would experience stress since the gears would be forcefully moved while rotating, it would shed a lot of metal in the process, breaking the transmission into bits of grinded metal and making the automobile inoperable.

How to maintain transmissions in Cars

A car's pressure plate is made of a sturdy metal that can withstand friction from constant connecting and detaching from an engine. Although this material is heavy duty, through time it would eventually wear out. Replacing an automobile's pressure is a hard task, and it includes bleeding the clutch line.

The clutch is a hydraulic system that uses fluid to compress and decompress the pressure plate. Meaning, when changing a pressure plate, it is mandatory to open the clutch line which can expose the line and accumulate air bubbles.

Air bubbles in the system will affect the performance of the clutch, so removing these bubbles and letting the line have pure clutch fluid running in them.

How to bleed a clutch?

In the hydraulic system of the clutch, there is a piston connected and it is the most important part of the system. This piston creates pressure that is a vital component in the activation of the pressure plate. This component is called the Master Cylinder and Slave Cylinder.

The Slave Cylinder contains a bleed screw that opens to release the clutch fluid. The most common way mechanics use to bleed the clutch is by putting pressure on the line of the clutch, and then opening the bleed screw.

This procedure is best when two people are working altogether yet doing it solo flight is a possibility. Just make sure to fill the roles of both people as explained.

• 1st Step (Locate the bleed screw)

The bleed screw is usually located under the engine on the driver's side. This will release the clutch fluid if rotated counterclockwise.

• 2nd Step (Pressurized the system)

Person A will be assigned to pump the clutch (pressing the clutch pedal and then releasing continuously) to put pressure on the system. Pumping the clutch more than once multiplies the pressure applied to the system that will later be bled.

• 3rd Step (Releasing the pressure with the air bubbles)

Person B will be assigned to open the valve from underneath when the pressure builds up. It will spit out the fluid together with the air bubbles. This is not a waste of clutch fluid because it is necessary to release it until the pure clutch fluid runs in the system.

The goal in this process is a solid stream of clutch fluid exiting from the bleed screw. This would mean that the air bubbles from the system are eliminated making your clutch work as if it was freshly released from the factory. Remember to supply an adequate amount of clutch fluid since the system is bleeding out.

What to do if the clutch won't bleed

Clutches can have multiple reasons as to why they are not bleeding and respectively, solutions. Checking leaks around the system can quickly diagnose the culprit of your "not bleeding" clutch. Or we should try these solutions step by step to avoid replacing working parts. This sequence is methodological and designed to analyze the problem from the smallest components up to the major components.

• Solution 1 (Copper Tube)

One of the most common reasons a clutch won't bleed is because the line that involves the clutch system is leaking. Check the copper tubing involved in your clutch for leaks because instead of providing pressure toward the slave cylinder, the system will leak the fluid and will not release the pressure in the bleed screw.

Certain methods can quickly seal the leak of the copper tubing but since the system is hardly pressurized, a repaired copper tubing can break the seal. The best thing to do is to replace the whole line of copper tubing.

Copper tubing can be replaced, and most shops have copper tubing that is molded in the specific way your car is designed to be. This can quickly solve the problem since copper tubing is abundant in the market and won't make you run through dozens of shops to buy one.

• Solution 2 (Bleed Screw)

If there is no leak in your copper tubing, then check the slave cylinder. Since slave cylinders are rarely meddled at, the components that are not moving can be stuck, like the bleed screw. The bleed screw can accumulate moisture that can cause rust which can then block the path.

Or just plain stuck since again, it rarely moves. There are bleeding screws available in the market that can replace the exact bleed screw your car has. Just simply buy a new bleed screw, remove the old bleed screw by unscrewing, and then place the new bleed screw.

This should assure you that the bleed screw is functioning and then you can start to bleed the hydraulic system again.

• Solution 3 (Bleed Screw Assistance)

Sometimes, forcefully pulling is better than forcefully pushing. Or replacing the bleed screw is not just enough. There are cases that a little siphon could help sip up the fluid to the bleed screw. Various aftermarket parts can suck the fluid in your clutch system.

A pump with a hose connected to the end of it is used to siphon the fluid forcefully. It connects to the bleed screw and will apply a vacuum to the system which will then force the fluid to flow out of the system. If the hose is transparent, then you can monitor the fluid being released by the system. If the hose contains a full stream of fluid, then the system is clear of air bubbles.

If the hose contains little bubbles, then you can pump and bleed again until the bubbles are removed.

• Solution 4 (Slave Cylinder)

Removing the bleed screw is to avoid replacing the whole slave cylinder. But if the clutch still won't bleed, then the slave cylinder can be the next reason. The Slave cylinder is a piston moving up and down to forcefully compress the fluid which creates pressure.

Just like shock absorbers, they too have gaskets that can be broken down by frequency of use. So replacing the whole slave cylinder can solve the bleeding problem. In this way, it assured you that there will be no malfunction occurring in your clutch system that is revolving around the slave cylinder.

Take note too that installing a new slave cylinder will basically reset the hydraulic system and clutch fluid will take time before reaching the slave cylinder.

• Solution 5 (Master Cylinder)

Since the slave cylinder is replaced, the issue won't be revolving anymore in the latter part of the system. This would lead you to question the functionality of the master cylinder. The master cylinder is in the firewall of the car in the driver-side area. Check for leaks in the piston, under the cup of the clutch fluid.

Basically, check the area of the master cylinder for leaks for it may be the reason that the pressure can't build up in the system to bleed the clutch fluid. This will prompt you to buy a new master cylinder that should ensure you with a brand-new clutch hydraulic system.

Conclusion

If you reach this part and the clutch is not able to bleed, then acquiring the services of a professional mechanic is the best choice. Doing it yourself can help minimize the costs.

Although sometimes a professional mechanic can diagnose the specific problem better and would lessen the risk of replacing the working components of the car. The clutch is a vital component of manual vehicles.

Assuring that the whole clutch hydraulic system works is a necessity since it could define the boundary between life and death. Always maintain your basic components to avoid a larger expense.