Q: Brake pedal goes soft

asked by on

The brake pedal goes soft, but I can pump up the brake.

I have seen this before. It is usually caused by an internally leaking master cylinder. The master cylinder is where the pressure for the entire brake system is developed. If it leaks internally, your pedal goes down, if you release it and step on it again you can build up some pressure. Eventually if you keep your foot on the pedal, it will go down again. Replacement of the master cylinder is the usual repair. This requires opening up the hydraulic system and bleeding any air that may be trapped in the lines. Not doing so will leave you with a very spongy feeling pedal. I suggest seeking the help of a qualified mechanic, such as one from YourMechanic, to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Brake pedal goes soft

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: Knocking sound.

A knocking sound within the engine is likely caused by low oil. I would first start by checking the oil level to ensure it is full. If the oil is low, you can top it off and see if anything...

Q: Overdrive not working

Greetings! You have a 4T65E transmission. A transmission used in the Pontiac Montana and Pontiac Aztek by GM for about 10 years. About 4 years into production they started receiving complaints about no overdrive and no fourth gear. It was...

Q: Engine puffs blue smoke; thumping noise at highway speeds

Hi there, thanks for asking about your 2004 Infiniti FX45. The blue smoke you notice on initial start-up is likely caused by worn exhaust valve stem seals. They allow a tiny amount of oil to get into the combustion chamber...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...