Skip the auto shop - Our mechanics make house calls

Q: Brake sinks slowly into the floor and have no leaks on master cylinder

asked by on

So when i drive the brake slowly goes down to the floor to the point were im still rolling and the brake doesnt go any further. but when i pump the brake i slowly regain pressure and i have checked all around the master cylinder and there have been no leaks.

My car has 125274 miles.
My car has an automatic transmission.

Hello. The master cylinder does not have to be leaking externally for it to be bad. The pedal sinking to the floor then coming back somewhat when you pump it is generally a tell tale sign that the master cylinder is bad. Have a local expert verify the problem with the brake system and replace the master cylinder if necessary.

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!
  • Home
  • Questions
  • Brake sinks slowly into the floor and have no leaks on master cylinder

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: Driver has to gas engine to prevent shutting down

Hello there, thank you for asking about your 1993 Isuzu Pickup. If you're getting 26 mpg in a 23 year old truck, that's as good as it gets. As far as the stalling out, there are many potential causes. Since...

Q: Cooling fan not coming on

Most of the time when the fan stops coming on it is caused by a fan failure. If the fan stops working it means that either the motor in the fan failed or it blew a fuse. If it blew...

Q: I got code P0016 and P0008. I just want to know what caused the problem and which one is bank 1 sensor A?

Hello, this problem (both codes apply to the same problem) relates to a calculated "bad timing correlation" between the crankshaft and the exhaust camshaft for cylinder 1 (cylinder head at front of the car). Engine management has tolerances for the...

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...
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.