Q: Could a leaking master cylinder cause the brakes to go to the floor very suddenly? 2004 Pontiac Grand Prix

asked by on December 17, 2016

So I'm pretty sure my master cylinder is bad. I was pressing my brakes down when I was parked, and they felt normal, but then went to the floor very suddenly. I was able to drive a mile home, but I could barely get brakes when I pushed all the way to the floor. Could a leaking master cylinder cause the brakes to fail so suddenly?

My car has 200000 miles.
My car has an automatic transmission.

Brake safety Inspection $94.99 - $114.99 Get a Quote

Hi - yes, a master cylinder problem, or a leak in the brake system anywhere, could cause "sudden loss of pedal". Check your brake fluid level first for low fluid. If fluid gets low enough that air gets in the system, the brake pedal will be VERY weak or spongy - air compresses, brake fluid does not. I would recommend a brake system inspection before driving any further by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I clean the rearview mirror?
A dirty rearview mirror is not only a nuisance to drivers, but a potential hazard. Do not spray any chemicals or glass cleaner directly onto the mirror. Instead, spray a gentle glass or household cleaner onto a soft, clean, damp...
Steering wheel bolt loose.
The vehicle shows it has a recall from the manufacturer for the tie rod ends coming loose or failing and driver may loose control. The recall number is 06V155000. My recommendation is to not drive the vehicle and contact your...
Car not turning over.
The starter is the most likely problem with your no crank condition. I would check for proper power getting to the starter main power cable and also a good signal to the small wire at the starter from the ignition...
Check Engine Light stays on - 2006 Jeep Liberty
Hello there, many faults can lead to the replacement of the purge solenoid on your 2006 Jeep Liberty. Without knowing the code stored in the computer I can only offer general advice. From your description it sounds like your vehicle...
How do I find the button to reset my odometer from trip to actual mileage on my Malibu
Hi there. Most GM vehicles from 2009 to current 2017 models utilize the Driver Information Center. A general introduction to this system can be found by watching this video (https://www.youtube.com/watch?v=GVD8d3w_mgE), but your owner manual in the glove box should provide...
Smoke coming out of the vents into the cabin compartment.
Hi there. The green ooze that you saw was indeed coolant. The issue could be the heater core hoses or heater control valve is leaking coolant and the ventilation system on your air conditioning system to the open air outside...
Car tilting after going over curb and impacting tree at 10 mph. Bumper bar is damaged, bumper arm broken. Side of impact is higher
The frame and/or suspension components have been damaged. To determine which will require some measurements and inspection. If all the damage is suspension related, that is assuming none of the sub-frame is damaged or the suspension mounting bosses, it is...
What does Gn10/1 mean when looking at the wiring for a fuse box?
The GN10/1 on a wire diagram at a connector should be the wire is green and the connector has 10 pins and green wire is in number 1 position.
Can the timing being off on my 2001 Toyota avalon cause the rpms to go up and down
Fluctuating RPM is not a typical symptom of a mispositioned timing belt. To rule a mispositioned timing belt in or out, though, check engine vacuum. If intake vacuum is 4-5 inches below spec., then that would be consistent with incorrect...

Related articles

5 Red Flags That Your Car Needs Immediate Attention
It It isn’t popular to think about, but you should be prepared for vehicle problems. Vehicles are designed and built by people, and they are only as perfect or flawed as the people who build them. That means sooner or...
The Best Used Cars to Buy for Occasional Drivers
Not Not everyone relies on their car on a daily basis. Maybe you aren’t the type that deals with a daily commute, and running from here to there constantly. If that’s the case, you may be looking for a car...
Pontiac Certified Pre-Owned (CPO) Car Program
If If you’re in the market for a used Pontiac vehicle, you may want to check out cars under their certified pre-owned program. Many manufacturers have a certified pre-owned (CPO) program, and each one is set up differently. Read on...