Low Clutch Fluid Symptoms

A half full clutch master cylinder reservoir
  • 1-2 hours
  • Beginner
  • 20-100
What You'll Need
Dot 3 or Dot 4 brake fluid as recommended by your manufacturer
Service manual
Funnel (optional)
Heavy-duty gloves
What You'll Need
Dot 3 or Dot 4 brake fluid as recommended by your manufacturer
Service manual
Funnel (optional)
Heavy-duty gloves

From motor oil and coolant to transmission fluid and power steering fluid, you must always keep a sufficient supply of fluids in your car to keep running smoothly. Clutch fluid is sometimes forgotten, but it plays a critical role in its overall health. Check out this article for info on clutch fluid, including what it is, how to tell when your clutch fluid is low, and how to refill clutch fluid when it needs replacing.

What Is Clutch Fluid?

Manual transmission cars have a clutch system controlled by a master and slave cylinder, both of which are lubricated with clutch fluid. When applying pressure to the clutch pedal, fluid pumps from the master cylinder to the slave cylinder, which forces the throw-out bearing. This system allows the clutch to release from the flywheel and change gears.

Overall, the clutch fluid acts as a hydraulic to help this heavy movement along. Clutch fluid is stored in the master cylinder and flows into the slave cylinder when the clutch pedal is depressed, but it never makes direct contact with the transmission fluid in the gearbox cavity.

Is Clutch Fluid the Same as Brake Fluid?

Yes. Brake fluid and clutch fluid are the same things. What you call them just depends on where the fluid is located in the brake system. Brake fluid is the fluid in the main brake line, while clutch fluid is found in the clutch master cylinder.

Is Clutch Fluid the Same as Transmission Fluid?

Clutch and transmission fluids are both used in automobiles, although they are very different. They have certain similarities in that they both have lubricating qualities. They also have several components in common, such as anti-rust and anti-oxidation compounds.

Aside from that, they're distinct in many respects, and you won't want to mix them up in your car lest you damage the internal components.

clutch fluid in open plastic container

How Often Should You Change Your Car’s Clutch Fluid?

Technically, you only have to replace your car's clutch fluid if there is a problem with the clutch mechanism. However, if you want to take care of your car, you should change it every couple of years to keep it fresh. Also, dirt can get into the system, meaning that the clutch fluid should be checked as frequently as the brake fluid.

While some will tell you that the clutch system is a "closed system," meaning that the clutch fluid should only be replenished if there is a leak, it's still a good idea to check it now and then for proper maintenance.

Contamination of the clutch fluid is a regular occurrence, and you generally do not want to have old fluid sitting. It is also highly recommended that you change the clutch fluid whenever the car has been sitting for a long time without being used.

If the fluid is not adequately maintained or inspected, it can substantially impact the vehicle's operation. It's dangerous to drive without adequate brake fluid.

Signs and Symptoms of Low Clutch Fluid

A problem with clutch fluid can cause the following problems:


hand changing gears in car

If you notice that shifting gears has become more complicated, it's possible that your clutch fluid is low or the flow has become obstructed. Switching gears should not be a jarring experience but rather a seamless one.

Stop and Go

Do you find yourself stopping or lurching forward while driving? This shuddering could indicate that you're running low on clutch fluid.

Overly Loud

Is your car making a little more noise than usual? Grinding of gears could be caused by a lack of clutch fluid or a faulty compartment, which, if ignored, could lead to additional (and more expensive) damage.

Slipping Gears

If your gear motions have slowed or become less sensitive, it's possible that your clutch fluid needs to be replaced. The longer you leave your car with these symptoms, the more difficult it will be to drive and the more likely you may have problems. It's preferable to solve the problem right away rather than later on!

Dark Fluid

When clutch fluid is new, it is a bright yellow tint that darkens over time, turning red or black as it becomes contaminated or aged.

What Causes Low Clutch Fluid Levels?

Clutch fluid levels can drop over time due to regular operation, but it's critical to rule out more serious issues.

You have a more significant problem if your leakage is persistent and you find yourself having to replace it frequently.

That usually indicates a leak in the system, which could show up outwardly (check for wet spots on the ground or under related components) or inside (look for broken seals inside the master or slave cylinders).

Leaks must be repaired as soon as possible, which is all the more reason to be cautious and regularly check your fluid levels.

How to Check If Your Clutch Fluid Is Low by Looking at Reservoir

clutch fluid in plastic container

One of the first things you should do when diagnosing clutch fluid issues is to check the level of the fluid. If it's too low that could be the main cause of most of your problems and you can move on to refilling the clutch reservoir.

First, before opening the hood, ensure the car is parked on a hard, flat surface then turn the engine off and allow it to become cool to the touch. The clutch fluid reservoir is found inside your vehicle's engine compartment, which is usually positioned beneath the front hood.

Next, look for a small clear tank located in the engine bay near the windshield. The clutch fuel reservoir is usually located near the windshield on the driver's side and will be clear with a black cap. Make sure you're looking at the proper reservoir by looking at the label on the cap.

Take note of the fluid level on the tank's side. Since these reservoirs are transparent, you should be able to see the fluid level without touching the tank. There will be lines labeled "minimum" and "maximum" on the tank's side.

Check sure the liquid level in the tank is near the maximum line towards the top or at the very least above the minimum line. If it's lower in the reservoir then proceed to refilling the clutch fluid reservoir.

If your car has a reservoir tank that you can't see through, you can use a dipstick to check the level. Lower the dipstick into the reservoir, retaining the handle until it reaches the bottom. Pull it back up and note how much fluid is on it. You should plan on topping off the tank with fresh fluid if it's less than 2/3 full.

Checking Clutch Fluid without Looking at Clutch Reservoir

There are also several ways to check to see if your clutch fluid is low without looking at the reservoir itself.

First, check to see if the clutch pedal glides smoothly. Sit in the driver's seat and push the clutch pedal down hard a couple of times.

When you press down on the pedal, it should travel smoothly and spring back to its original position every time, but if you're having trouble moving the pedal consistently, the clutch fluid level is most likely low.

You should also test your ability to shift gears while operating the clutch by driving the car. Start the car in first gear and press down on the clutch to accelerate, and when the engine reaches around 2,000 RPM, press it again to move into second gear.

Keep an eye out for anything unusual, such as a lurching car, a jammed clutch, or grinding sounds. These are other signs of low clutch fluid needing to be replaced or refilled.

Step by Step Guide to Refilling the Clutch Fluid Reservoir

clutch fluid in open reservoir

Step 1 - Choose the Fluid

The first step should be to choose a clutch or brake fluid that your owner's handbook says is safe to use. The manufacturer may recommend one of several fluids, so read your owner's manual to see which one is best for your vehicle. DOT 3 or DOT 4 braking fluid is used in most cars.

Keep in mind that the clutch fuel reservoir contains the same type of brake fluid as the brake fluid reservoir. Use the type of fluid specified on the clutch tank cap or in the owner's handbook to avoid causing damage to your car.

Step 2 - Prep for Safety

Before handling the fluid, put on rubber gloves and for added protection, consider putting on a long-sleeved shirt. Clutch fluid is corrosive and can be dangerous if not handled properly.

If you get any liquid on your skin, wash it off immediately and avoid touching your eyes or mouth until your hands are clean. Wipe up spilled fluid as soon as possible with paper towels, especially if it gets on your vehicle's painted surfaces, and wipe up larger spills with an absorbent material like cat litter.

Step 3 - Fill

Fill the reservoir with fluid until it is about 2/3 full. Consider placing a plastic funnel on the reservoir and always pour slowly to prevent the liquids from spilling and make sure. If the reservoir has a maximum marker, fill it to that level as it doesn't have to be full.

If the tank is excessively full, the fluid may spill or otherwise flood the clutch system of your car.

Step 4 - Close Up

Finally, close the hood and replace the reservoir top. The inside of the cap contains a rubber gasket, so turn the cap clockwise until it locks into place, making sure it sits securely over the reservoir hole as otherwise it could leak fluid or let air into the reservoir.

Air obstructions can be a major problem for a clutch system's proper operation, and the only method to get rid of them is to empty the fluid.

Extra Steps

As an extra precaution, remember to dispose of all fluids properly. While any new fluid left over is acceptable for a short period, it should not be utilized beyond a few days since it will collect moisture from the air. Simply dispose of the remaining fluid with the old fluid.

It's a breeze to add clutch fluid! Check your owner's handbook to ensure you're using the correct fluid, which is usually DOT 3 brake fluid or hydraulic clutch fluid, and then get to work. The most important thing is to ensure sure the fluid does not come into contact with your skin and that it is poured into the correct reservoir.

Keep an eye on fluid levels to avoid leaks, especially if you detect any warning signals. If adding fluid doesn't solve the problem, or if the levels continue to decline, you may need to do further investigation or take it to a mechanic for a second opinion.

For more, check out this article on Everything You Need to Know About Brake Fluid or Basic Brake Repair Instructions for those pesky brake issues.