2008 Dodge RAM 1500 Brake Service (ONLINE REPAIR MANUALS)

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 ...

Manual

• Remove reservoir filler caps and fill reservoir with proper brake fluid.
• If calipers or wheel cylinders were overhauled, open all caliper and wheel cylinder bleed screws.
• Close each bleed screw as fluid starts to drip from them.
• Fill master cylinder reservoir once more before proceeding.
• Attach one end of bleed hose to bleed screw and insert opposite end in glass container partially filled with brake fluid, Fig. . Ensure bleed hose is immersed in fluid.
• Open up bleeder, then have an assistant press down brake pedal.
• Once brake pedal is down, close bleeder. Repeat bleeding unt...

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...

Brake Lines & Linings

Remove one of the front wheels and inspect the brake disc, caliper and linings. The wheel bearings should be inspected at this time and repacked if required.

Do not get any oil or grease on the linings. It is recommended that both front wheel sets be replaced whenever a respective pad is worn or damaged. Inspect and, if required, replace rear brake linings also.

If the caliper is cracked or fluid leakage through the casting is evident, it must be replaced as a unit.

Brake Roughness

The most common cause of brake chatter on disc brakes is a variation in thickness of ...

RWAL System

This system prevents rear wheel lock-up by monitoring wheel speed and altering pressure to the rear wheels. The system uses one sensor mounted on the rear differential to determine if the rear wheels are locking up. This system has a "passive" rear wheel control (meaning rear brake pressure during anti-lock braking is provided by the master cylinder). Rear brake fluid application is controlled according to wheel speed, degree of wheel slip and rate of de...