ABS Accumulator Replacement Cost

Know what price you should pay to get your vehicle fixed.

The average cost for an ABS accumulator replacement is between $422 and $446. Labor costs are estimated between $87 and $111 while parts are priced at $335. Estimate does not include taxes and fees.
Note about price: The cost of this service or repair can vary by location, your vehicle's make and model, and even your engine type. Related repairs may also be needed. Talk with a RepairPal Certified shop to learn which repairs might be right for you.

What is an ABS Accumulator?

Anti-lock brake systems use several components to safely and effectively slow and stop a vehicle and prevent skidding. This is a form of brake assistance which uses a pump motor to pressurize brake fluid inside the ABS modulator, and that high pressure brake fluid will be released in short bursts to slow the vehicle for the driver in the quickest and safest manner. Since a pump is used to pressurize the brake fluid, the ABS accumulator is used to store pressurized brake fluid to prevent the ABS pump from running each time the brakes are pressed. This increases the life of the ABS pump and strain on the vehicle's charging system.

How does the ABS Accumulator work?

The ABS accumulator acts as a storage device for high pressure, but there is more going on inside this small metal can than expected. The ABS accumulator is pre-filled with an inert gas at high pressure, and the gas is separated from the brake fluid reservoir by a diaphragm. As brake fluid is pumped into the accumulator, it forces the diaphragm to expand and compress the inert gas. The compressed inert gas then pushes the diaphragm, forcing brake fluid out of the accumulator at constant pressure when the driver brakes.

What are the symptoms of a bad ABS Accumulator?

Since the job of the ABS accumulator is to provide high pressure brake fluid, it is accompanied by a sensor that provides feedback to the driver in the case that brake fluid pressure is too low coming from the accumulator. The brake fluid pressure sensor will notice the brake fluid pressure is too low and signal the driver with the ABS and brake warning lights when the brakes are pressed. These lights may remain illuminated, or cancel moments after the brakes are released. ABS fault codes will be stored, and will point to low brake fluid pressure.

Can I drive with a bad ABS Accumulator?

After driving a vehicle for any length of time, the driver will become accustomed to the road manners of that vehicle, and sudden changes to safety features and driver assistance systems may lead to unpredictable operation. That being said, the normal brakes will be functional when the ABS accumulator is faulty, but the vehicle will be prone to skidding in an emergency situation or during inclement weather. As a general rule, if the brake or ABS warning lights appear, or the brakes do not function properly, the vehicle should be serviced immediately.

How often do ABS Accumulators need replacement?

Accumulator failure is not typical of any vehicle, but the issue does occur. Since this is a pressurized component, any loss of pressure in the container due to corrosion, wear of seals, or physical damage will require the ABS accumulator to be replaced. Premature failure may be avoided by flushing the brake fluid as required by the manufacturer. In general, most vehicles will not require replacement of the ABS accumulator.

How are ABS Accumulator issues diagnosed?

Diagnosis of the ABS brake fluid accumulator is simply done. The servicing technician will read codes from the vehicle that relate to the ABS system, and, if the code returned refers to low brake fluid pressure, the operation of the brake fluid pressure sensor and ABS pump motor must be tested. Once those two components are confirmed to function, the ABS unit will be pressurized, and the brakes will be pressed repeatedly to verify that pressure bleed off is occurring prematurely.

How are ABS Accumulators replaced?

In many vehicles, replacing the ABS accumulator requires replacement of the ABS modulator assembly, which may also include the ABS control module. If the accumulator has failed the self test procedure, and it can be replaced independently, the repair is not typically difficult. First, brake fluid pressure is released from the ABS accumulator to prevent spraying brake fluid once removed. Then, the fasteners securing the accumulator will be removed, and the new accumulator and seals will be installed on the ABS hydraulic unit. Finally, the ABS hydraulic unit and service brakes will be bled of air and tested for proper function.

RepairPal Recommendations for ABS Accumulator issues

Flush and refill the entire brake system when replacing major components. Any debris or contamination from these components may remain in the system and cause repeat failures. Also, the amount of air entering the brake system and ABS system dictates that the system is thoroughly bled to ensure the service brakes remain operational.

What to look out for when dealing with ABS Accumulator issues

The ABS accumulator may be small, but it is under very high pressure. Avoid physical damage to the ABS accumulator, even after it is out of the vehicle. Even when there is no load on the diaphragm, the inert gas inside the canister is still pressurized.

Can I replace the ABS Accumulator myself?

Replacing the ABS accumulator is not a difficult task, but a thorough knowledge of hydraulic brake systems and anti-lock brake systems is necessary. Diagnosis can be reached easily with the instructions, but opening the brake system, especially at this high pressure area, can cause injury or render the service brakes useless. If you have any concerns about completing the task, or lack the experience needed, allow a professional to handle this repair.

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