2008 Dodge RAM 1500 Brake Service (ONLINE REPAIR MANUALS)

Master Cylinder

Except Caravan & Town & Country

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. The equalization feature does not affect circuit separation in the event of a front or rear brake fault. The reservoir compartments will retain enough fluid to operate the functioning hydraulic circuit.

Caravan & Town & Country

The body...

The only serviceable power brake booster components are the vacuum hose and the check valve. The power brake booster must be serviced as an assembly. If diagnosis indicates a power brake booster fault condition, the unit must be replaced as an assembly.

Replacement

Caravan & Town & Country

• With engine stopped, pump brake pedal four or five times to deplete power booster vacuum.
• Disconnect both battery cables, then remove battery thermo guard and battery from tray.
• Remove air inlet resonator and hoses as an assembly from throttle body and air cleaner housing.
• Remove coolant fi...

Master Cylinder/Power Booster Test

• Start engine and inspect booster vacuum hose connections for leaks.
• Stop engine and shift transmission into neutral.
• Pump brake pedal until all vacuum reserve in booster is depleted.
• Press and hold brake pedal under light foot pressure. Pedal should hold firm. If it falls away master cylinder is faulty.
• Start engine and note pedal action. Pedal should fall away slightly under light foot pressure, then hold firm.
• If no pedal action is felt, the power booster, vacuum supply or vacuum check valve are faulty. Proceed to "Power Booster Vacuum Test."
• If p...

Pedal Falls Away

• System leak at brake line, fitting, hose or caliper/wheel cylinder.
• Internal leakage in master cylinder caused by worn or damaged piston cups.
• Internal leak in ABS or RWAL system.

Low Pedal

• Worn brake linings.
• Worn drums or rotors.
• Rear brakes out of adjustment.

Spongy Pedal

• Air in hydraulic system.
• Thin brake drums.
• Substandard brake lines and hoses.

Hard Pedal Or High Pedal Effort

• Linings that are water soaked, contaminated or glazed.
• Faulty power booster or check valve.

Pedal Pulsation

• Disc brake rotors have excessive lateral runout or thickness variation.
• Out of round brake ...

These self contained vacuum hydraulic power braking units are of the vacuum suspended type. They use engine intake manifold vacuum or a vacuum pump along with atmospheric pressure for their power, eliminating the need for a vacuum reservoir. A mechanically operated control valve, with integral vacuum power diaphragms, controls the degree of brake application or release depending on amount of foot pressure applied to...

Brake System Bleed

The anti-lock brake system must be bled any time air enters the hydraulic system. It is important to note that excessive air in the brake system may set a primary pressure diagnostic trouble code in the control module.

Pressure or manual bleeding procedures can be used when bleeding the ABS system after hoses or brake lines have been disconnected. Bleeding the ABS hydraulic system is also necessary after replacement of the hydraulic assembly or wheel brakes. During bleeding procedures, ensure the brake fluid level remains close to the Full mark on the reservoir.

T...