Durango 4WD V8-5.9L VIN Z (1998)
Brake Master Cylinder: Description and Operation
A two-piece master cylinder is used on all models. The cylinder body containing the primary and secondary pistons is made of aluminum. The removable
fluid reservoir is made of nylon reinforced with glass fiber. The reservoir is the only serviceable component.
The fluid compartments of the nylon reservoir are interconnected to permit fluid level equalization. However, the equalization feature does not affect
circuit separation in the event of a front or rear brake malfunction. The reservoir compartments will retain enough fluid to operate the functioning
hydraulic circuit.
Care must be exercised when removing/installing the master cylinder connecting lines. The threads in the cylinder fluid ports can be damaged if care is
not exercised. Start all brake line fittings by hand to avoid cross threading.
The cylinder reservoir can be replaced when necessary. However, the aluminum body section of the master cylinder is not a repairable component.
NOTE: If diagnosis indicates that an internal malfunction has occurred, the aluminum body section must be replaced as an assembly.