National average cost of a Master Cylinder Replacement for popular vehicles:
Avg. cost $150
Ram ProMaster 2500
Avg. cost $600
Avg. cost $149
What is a master cylinder and how does it work?
The master cylinder is a hydraulic pump, a component of a vehicle's braking system. Whenever you apply pressure to the brake pedal, a piston moves inside the master cylinder. The piston exerts force on the hydraulic oil (brake fluid) inside of a network of tubes that run along the underbody of your vehicle. That pressure is used to actuate the brake calipers (in the case of disc brakes) or wheel cylinders (with drum brakes) attached to the hubs at each wheel.
What are the signs that a master cylinder needs to be replaced?
A master cylinder is made to last the lifetime of a vehicle. Unfortunately, like many other mechanical devices, master cylinders sometimes fail. When your master cylinder is not working as it should, you will notice certain symptoms. Since the brakes are the most important safety feature of your vehicle, the following signs should not be ignored
The brake pedal feels soft or spongy when you press it
The pedal has little resistance and sinks to the floor
You notice a reduction in braking power, or stopping distances increase
SUBSCRIBE FOR UPDATES
Sign up for our newsletter to get the latest news and deals straight to your inbox
There are 50 shops within 20 miles of your location.
The master cylinder is located at the top end of the brake system and includes the brake fluid reservoir. To replace the component, the brake fluid must be removed from the reservoir. This can be done by either bleeding the brakes enough to empty both the master cylinder and the reservoir, or by using a pump, siphon, or baster. Once the old master cylinder has been emptied, a mechanic will typically take the following steps to perform the service
Disconnect and remove any components that are in the way of access to the master cylinder
Unplug the brake fluid level sensor wire
Loosen the brake line fasteners, taking care to prevent rounding off the edges
Remove the fasteners that secure the master cylinder in place
Prepare the new master cylinder by “bench bleeding” the unit
Completely loosen the brake line fasteners to detach them from the old master cylinder
Remove the old master cylinder
Transfer the reservoir to the new master cylinder
Set the new component into its mounting location, taking care to ensure that the rod coming from the brake booster fits properly into the master cylinder, and start the fasteners
Connect the brake lines until they are finger tight
Tighten the mounting fasteners and the brake lines
Reconnect any components that were removed
Add fresh brake fluid and bleed the system
Test drive the vehicle to verify the repair
OTHER QUESTIONS CUSTOMERS ASK
What parts are related to a Master Cylinder Replacement?