How to flush hydraulic clutch? Why does the clutch pump make air? Why does the clutch pedal become so soft?
Your vehicle’s clutch system works in the same way as your brake system. Brake fluid is the most common working fluid for clutch systems. Through hoses, the clutch pedal is connected with the slave cylinder. Brake fluid flows from the master to the slave cylinders when the pedal is pressed down. This creates the pressure needed to engage the clutch. This is how gears can be changed easily.
A lever-operated mechanical clutch is available for classic cars and trucks. These systems use connecting rods to activate the pressure plate when the clutch pedal is pressed. A hydraulic clutch system is used in new vehicles. They are easy to install and take up less room. They do not need to be adjusted as the printing plate wears. Hydraulic clutch systems are more comfortable and easy to use for shifting gears. The majority of hydraulic clutch systems come with an additional master-cylinder. Some vehicles, however, use the same mastercylinder for the brake system as the clutch system.
The hydraulics need to be drained for routine maintenance such as changing vehicle fluids or repairs such as replacing the slave-cylinder. Air bubbles build up and stop the hydraulic system from functioning properly every time you turn it on. Air must be taken.
If the system contains air, when you press the clutch the air bubbles will trap and absorb most of the fluid from the master to the slave. This prevents the slave from performing its task. Your clutch pedal will not be able harden as it should if the slave cylinder doesn’t have the necessary fluid pressure. This can make gear changes more difficult.
How to Bleed the Hydraulic Clutch Systems?
Bleeding the clutch means that you need to drain some hydraulic fluid. You don’t have to do this unless there is a problem with the clutch. If your clutch pedal is not working properly and the pedal does not move when you press it, then the problem could be due to the air in the clutch. This is only for vehicles with manual transmission.
Check the hydraulic level of the reservoir first, and if necessary, top it up with the same fluid.
Push or pull the air through the fluid line from the slave cylinder to remove air from the clutch system. You will first need to attach a flexible hose to the bleeder valve’s nipple. If you use a clear hose (like aquarium hose, serum, etc.) It can be difficult to see the entire system’s airflow if you use a clear hose (such as an aquarium hose, serum, etc.). Vacuum pumps are the easiest way to expel the liquid and any air from the system. The hydraulic reservoir’s lid should be sealed tightly. Push the vacuum pump through a discharge valve until you see no air bubbles. Ask a friend if you don’t own a vacuum pump. Your friend can help you pump the clutch pedal several times while keeping the relief valve open. Then, hold the lever down until it is fully compressed. Use your wrench to loosen the drain valve screw by about half turn. The drain valve should be transparent and you will hear the hissing sound. Close the drain valve tightly with the clutch pedal depressed. Your friend should take their foot off of the clutch pedal, and then top up the hydraulic fluid within the reservoir. Keep going until the hissing sound stops and no more air bubbles escape from the purge valle. When the purge is completed, the clutch pedal should have been hardened.
Make sure to shut off the drain valve after you are done. Take a test drive. To ensure that liquid doesn’t leak, you can place a sheet of white paper underneath the car while it is parked. You must tighten the drain valve if there is a fluid leak.
Do not drain all fluid from the clutch system. You will need to start from the beginning if you do not completely drain the fluid.
