Skip the auto shop - Our mechanics make house calls

Q: My car brakes are spongy

asked by on

Replaced master cylinder today bled lines and pedal is still spungy new pads rotors calibers but the pedal is still spungy help

My car has 204000 miles.

A: When replacing a master cylinder, it should...

When replacing a master cylinder, it should be "bench bled" before installing it in the vehicle. This involves filling the reservoir with fluid, connecting rubber hoses to the brake line ports and placing the other end in the fluid reservoir, then operating the master cylinder piston. This make sure all the air is out of the master cylinder itself before installing it. Since you have already installed it, you should try bleeding fluid at the master cylinder, then work your way around the vehicle and bleed the system from each wheel again. If you do not have a bleeder, have a friend assist you. Have your friend pump the brake pedal 2 or 3 times, then hold the pedal. Crack a brake line loose at the master cylinder, making sure your helper does not press the brake pedal completely to the floor as you open the brake line. I usually place my other foot under the brake pedal when foot-bleeding. Repeat this 2-3 times with each brake line at the master cylinder, then re-bleed the system from each wheel, making sure to start at the wheel furthest from the master cylinder and finishing at the closest. If this does not help, then try removing the master cylinder and bench bleeding it, or have a certified technician look into the spongy brakes for you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My car has been stalling out on me.

This may be a sign of a failing idle air control valve. The idle air control valve is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being injected...

Q: The engine stutters for a while before starting. 2002 Honda Civic

Hi there - if your car stutter-starts, but runs fine once it is running, you probably have a problem with the fuel system check valve. This valve maintains some fuel pressure in the system so that your car starts faster...

Q: What is the function of the two sensors located at the clutch of the car. I know that the upper switch is the safety clutch switch

Hey there. The second sensor is the cruise control deactivation switch. If you push in the clutch when the cruise control is on, this switch shuts it off. If you do not have it connected, then most likely the cruise...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.