A clutch master cylinder is a component of any car with a manual transmission. It gives the hydraulics for the clutch. If you start to feel or hear something unusual when you shift gears or press the clutch pedal down, pay attention because it may indicate a problem with your master cylinder. If you have a bad clutch master cylinder then you will probably see some of these signs. Keep in mind, these sign can be the result of other issue within the transmission as well but they are good to look for if you suspect a master cylinder issue.
A “soft” pedal is a situation when you can feel with your foot that the pedal has lost most of its normal resistance as you press it down. This can be because of a leak in the master cylinder or the slave cylinder. The leak may be because of a problem with the seals.
HARD TO SHIFT
If it is difficult to shift gears this is a sign that the master cylinder is going bad. When you cannot depress the clutch normally it can be difficult to change gears.
PEDAL STUCK TO THE FLOOR
If your clutch pedal will not rise from the floor, then the hydraulics to the clutch are not working at all. Most likely the master cylinder has fail and will need to be changed immediately. You cannot drive the car in this condition.
If you discover that the transmission fluid is low and you have to refill it more often than you should then you probably have a leak. This leak may be issuing from the master cylinder. It could also be a crack or hole anywhere in the transmission system. All component of the transmission should be inspected for leaks to know the problem.
FLUID RISE IN THE RESERVOIR
If you have a bad master cylinder then you can carry out the following test with the help of an assistant. Have someone press down on the clutch while you look to see if the transmission fluid in the reservoir goes up when the clutch is down and then rises again when the clutch is released. If it does then your master cylinder needs to be changed.
If you are at a light with the brake on and the car in gear you may hear a loud noise as you hold down the clutch pedal. The cause of this may be that the master cylinder is leaking and won’t hold the release fork when the pedal is pressed down.
OIL ON THE CYLINDER
If you still are not sure what the issue is then take a look under the hood, and examine the master cylinder itself. If the bottom of the cylinder looks and feels wet and oily then the leak is probably from the master cylinder.
A failing clutch master cylinder will lose its ability to maintain the hydraulic pressure required for the clutch to function.Handling repairs of the cylinder will protect you from damaging your whole transmission, so be sure to have it worked on right away.