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.

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: Buzzing noise inside dash 2002 Dodge Dakota

Hi there - several possibilities here for a buzzing sound, as this is not an uncommon issue. Quite possibly the auto shutdown relay or the fuel pump relay are buzzing due to burned contacts. There are also instances where the...

Q: I'm getting a burning plastic like smell after a 45 minute drive but all gauges read normal and fluids look good.

Check the brakes out on the front of the van. It is possible that the pads are not releasing properly and burning the brake pads causing the plastic burning smell. The brake system could be sticking and not retracting causing...

Q: Car dies when put into gear

Hi there. From the description you have given, of your vehicle's engine dieing, it could be several things. Assuming, there is no Check Engine Light on, leads me to believe, the vehicle computer is not recognizing the fault. It could...

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.