Not in all cases. Some early generation ABS systems use a flashing dash light sequence to identify trouble codes. Most other domestic and import systems require a scan to retrieve codes.

The most common diagnostic tool used to check sensor operation is a scan tool. DVOM (digital volt/ohm meters) can be used to verify continuity, resistance and voltage output. An emerging tool is a hand-held scope for finite sensor operation.

Both conventional and ABS braking systems are bled in similar fashion. Certain ABS systems require the use of a bi-directional scan tool to cycle internal solenoids to purge the system of air. You should always check the service manual for the manufacturers recommended procedure.

As a general rule, whenever a master cylinder is replaced it must be bled along with the ABS HCU to ensure proper system operation.

The most common cause of ABS activation at low speeds where an intermittent WSS (Wheel Speed Sensor) signal is present is metal filings on the magnetic section of the WSS. Carefully inspect the tone rings with a magnifying glass for cracks and chips.

The easiest method is to deactivate the ABS system by pulling the fuse and performing several moderate speed stops to determine the reason for pull in the foundation brake system. Also, check history trouble codes to verify erratic ABS operation.

The most common reason for low pedal after brake service is improper adjustment of the rear drum/shoe or disc brake assembly.

A spongy pedal is an indication that air is still present in the brake system. Follow proper brake bleeding procedures and sequences. Use a plastic mallet to lightly tap hydraulic components to help free entrapped air bubbles from inner walls of calipers and wheel cylinders.

The easiest method is to deplete air from the vacuum booster by pumping the pedal until it's hard. Next, with the engine off, hold foot firmly on the brake pedal and start the engine. The pedal should drop slightly with engine vacuum and become firm if power booster is operating correctly. If hard pedal condition still exists check for binding linkage or over adjusted drum/shoe assemblies.

The best method is to isolate the brake system circuits and components with the use of proper brake system block off plugs. We no longer recommend the use of brake line clamps. There are many OE hoses that can be damaged by this type of clamp. By removing them one at a time and from side to side, it's easy to determine which component is at fault. Please contact the Answerman for more troubleshooting tips on this issue.

Through the use of a special brake measurement tool known as a go/no-go gauge it is easy to determine the correct booster push rod adjustment.

First, define the nature of the noise. With the engine running apply the brakes and listen for irregular noises. A whine usually indicates low fluid (power steering). A gurgling or rumbling noise indicates air in the system. A pulse thump indicates trapped air in the hydroboost circuit.

Check the service manual as procedures differ by year of manufacture date. Adjustment procedures require the vehicle to be raised on a frame engaging lift. Some models call for the rear axle to be suspended which allows full extension of valve's mechanical control arm. Use of line pressure gauges is required to verify correct valve operation and output control. Some Caravans have problems with the brake light switch holding slight pressure in the calipers.

First, verify the foundation brakes are adjusted correctly. Next, verify parking brake mechanical and cable operation. Adjust the parking brake to create a slight drag. Apply and release the parking brake several times to ensure correct operation. Procedures are different for caliper actuated systems.

Define the "source" and conditions from where noise occurs. Excessive noise can indicate potential brake system problems such as lining wear limit. Noises such as squeaks, squeals, grinds and growls are related to brake hardware needing replacement and proper rotor finishing and break in. . Operation of ABS and its related component noise such as clicks, motor/pump cycling and pulsing are normal.

The most common cause of pulsation is improper wheel lug nut torque procedures. These vehicles also require the use of an on car brake lathe to match the rotor to the hub. Any other machining method will result in eventual pedal pulsation.

If no excessive pulsation, lateral runout or surface scoring exists and physical dimensions of the rotor are within manufacturer's specs and you are using the same type and manufacturer of friction material- rotors machining is not necessary.

To insure optimal brake system operation. The grade of friction material selected can alter brake system balance and dynamic control. Premium grade material provides optimal brake performance under all conditions while delivering maximum life and durability. Using lower grade materials may provide sufficient stopping power but can compromise lining life and sensitivity performance.

A series of controlled moderate speed stops (15-20 Stops from 30-mph w/30 sec cool down) is required to properly "burnish" or break-in a new set of pads. During this initial stopping period, the process of lining transfer from the disc pads to the rotor surface helps condition the rotor surface to properly seat the brake pads. All pads are cured and all pads need to be burnished.

This is an indication of moisture sensitivity of the friction material. The use of Premium grade friction material will lessen the likelihood of this condition.