The proper fluid level in the reservoir is usually marked on the reservoir.The reservoir is normally mounted to the top of the master cylinder or is part of the master cylinder assembly.The hydraulic system does not consume fluid; therefore, if the fluid is low, check for leaks at the master and slave cylinders and the connecting hydraulic lines.Fill the reservoir only to the fill line to allow the fluid to rise as the clutch disc wears.Overfilling the system will cause slip and premature failure.Air can enter the system through the compensation and bleed ports if the fluid level in the reservoir is too low.The system must be bled to remove the trapped air.