Does your pedal go all the way to the floor when you press it? That means there is no brake pressure. Read on to find out how to solve the problem and get your brakes healthy again.
How Does the Brake System Work?
Whenever you press the brake pedal in your car, a plunger inside the brake master cylinder pumps brake fluid through break lines to the brakes. The brake fluid serves as pressure to the brake pads. The brake pads squeeze the brake discs or push the brake shoes to the brake drums.
Warnings of Brake Pedal Problems
If you are not sure why your brake pedal goes to the floor, look for other signs:
Brake warning light – Most cars come equipped with a brake warning light on the dash. Most times, the brake warning light activates when the brake fluid is low or leaking, the brake pads are worn, or the brakes themselves need to be replaced. However, it may also activate when the brake master cylinder is causing problems.
Check Engine Light Activated – When the brake master cylinder goes bad, the check engine light (CEL) may activate. This happens especially in newer model cars. Sensors inside the master cylinder detect issues and report them to the computer in your car. Drops in brake pressure are commonly reported. Other circuits involved may also trigger the Check Engine Light (CEL). This may also mean that there is more wrong with the braking system than the brake master cylinder.
Check the OBD2 codes – When your braking system performance goes bad, the computer in your car makes a record of each event. You can use an OBD2 Scanner (view on Amazon) to check the trouble codes that have been thrown about your vehicle. The troubles codes help to diagnose many potential problems under your hood. More than one code may be thrown for your braking system as well as for other components that are associated with your brakes.
Causes of Brake Pedal Goes to Floor
The healthy system operates smoothly and quietly on the road. Here are some causes of a disruption in the flow of the brake system:
Low Brake Fluid/Leak – The vale and piston seals inside the brake master cylinder can start to leak after the car has been driven for many years. The brake fluid absorbs water through air over time. The flat sealing washer may become hardened and fails to seal. The bore inside the master cylinder becomes corroded which causes leaks in the seals. The color of the fluid in the reservoir is no longer a healthy color. In these cases, the leaks can be identified and the seals can be replaced.
Contaminated brake fluid – When the brake pedal is depressed, the force transfers to the brakes using brake fluid. When the rubber seals on the brake master cylinder wear out, the brake fluid can become contaminated. When the fluid goes bad, it turns to a darker color. The brake pressure is also affected by the worn seals.
Damaged brake calipher – The brake calipher squeezes the brake pads against the brake rotor when you are trying to slow down or come to a stop. When the brake calipher is damaged, it starts to stick, which causes the vehicle to vibrate. As you travel at higher speeds, the shaking is accompanied by a burnt odor. You can tell which wheel has the damaged calipher by smelling around each wheel.
Bad Master Cylinder – The brake master cylinder is the heart of the automatic braking system along with brake fluid. When every component of the brake master cylinder is not working at its best, problems arise which must be addressed. When the brake master cylinder malfunctions, it shows in the brake pedal. The brake pedal will feel mushy when you press it when the brake master cylinder is gone bad. The pedal may also sink all the way down to the floor when the brake master cylinder is bad.
You Treat Your Car Badly – Most vehicle owners understand that a vehicle must be inspected and serviced from time to time, as referred to as routine maintenance. For those who don’t, the likelihood of problems that cause brake problems is extremely high. If the vehicle is not inspected routinely, small problems can escalate to major problems that are much more expensive to fix. This is also true for vehicles which sit for long periods of time.
If you want to avoid brake problems or other issues and save $100s of dollars that you’ll spend at the auto repair shop, you’ll need to service your vehicle often – you can use our mechanic-rated Auto Maintenance and Repair Manual to do this. It’s basically what mechanics use to go through your vehicle to check if there are any problems that need fixing. As soon as they notice the most minor problem, they’ll ask you to fork out some money even though it’s a problem you can fix yourself in minutes – the manual will teach you how to maintain your vehicle every few thousand miles and it’ll teach you how to fix minor problems that mechanics will ask you to pay for; saving you money in the long run.
A lot of our readers have the Auto Maintenance and Repair Manual printed on their garage wall and 92% of them haven’t visited the auto repair shop in the last year because they know what to do to avoid problems. All it takes is giving your vehicle a little attention every few thousand miles and you’ll never spend money at the workshop again.
How to Fix Brake Pedal Goes to Floor
The first step to fixing the problem is to identify why the pedal is not working. Once you’ve identified the problem, here are a few things you can do to solve the problem:
Fix it yourself -If you were able to check the OBD2 codes and you’re ready to get it fixed, do it yourself. When doing a brake job, it does not only mean changing the brake pads. It means removing rust from contact areas, cleaning off dirty grease, and apply new lubricant to make sure the parts can move about freely.
Two of the most common options are to bleed the brake system and change the brake pads. Here are the steps to bleed the brake fluid from the system:
Bleed the brake system
Typically, the brake fluid is designed to last for the lifetime of your car, or close to it. However, sometimes it must be changed. The fluid may have lost moisture resistance which means it has begun to absorb water. Air even becomes trapped in the brake fluid. When the fluid is not healthy, it causes big problems in the braking system. Here are the steps to bleed the brake fluid and refill with new fluid that will perform correctly:
1. Check your owner’s manual to confirm the right types of brake fluid. It is not a good idea to mix types. You can also ask the auto parts store clerk which kind you need for your car’s make and model. Purchase two or three of the 12 ounce cans of brake fluid.
2. Use a jack to raise your car up on a garage floor or somewhere equally as flat. Remove all four wheels. It is not advised to prop the car up on cylinder blocks. If you do not have the proper jack, take your car in to a repair shop.
3. Find the four caliper bleeding screws and try to gently remove them. If they don’t loosen, use an oil loosening spray to get them off without stripping them. Only have one screw loose at a time to keep the unnecessary air out.
4. Check the fluid level in the brake master cylinder reservoir. If you are not sure where it is, check your owner’s manual. The fluid level should be at the “full” mark.
5. Place tubing over the bleeder screw for the first brake you intend to bleed. Hang the catch container directly above the bleeder screw.
6. Have someone else pump the brake pedal several times until resistance can be felt after pressing the brake pedal. Maintain the pressure.
7. Open the bleeder screw. After the fluid is drained close the bleeder screw.
8. Check the fluid level in the master cylinder reservoir. If the fluid level is low or it is empty, make sure to replenish it.
9. Repeat these steps on each bleed screw as many times as necessary to regain pressure in the brakes with clean brake fluid.
10. Make sure the bleeder screws are replaced tightly and there is no fluid eruption when you use the brakes.
Change the Brake Pads
Changing the brake pads on your car increases performance and safety. If you don’t know how to operate a jack, let someone else do it:
1. Gather a ratchet and a car jack as the tools you’ll need.
2. Loosen the lug nuts on each tire and position the floor jack under the car.
3. Remove the lug nuts and the caliper bolts, then set them aside. Remove the tire so that you can see the caliper and rotor assembly..
4. Remove the old brake pads from both sides of the rotor.
5. Install the new brake pads. First grease the new pads around the metal plates. Only use a very small drop of the lubricant.
6. Adjust the caliper assembly to fit the new brake pads and finish with a socket wrench.
7. Reinstall the tires. Tighten the lug nuts by hand. Re-insert the jack and lift your car up enough to be able to remove the jack stand. Secure the nuts using a tire iron.
8. Lower the car and remove the jack.
If neither of those fixes solve the problem, you can try changing the seals on the master cylinder:
Replace the seals
The seals in the brake master cylinder can be replaced with a few tools. If you want to try to replace the seals yourself, gather a set of tools and a towel and follow these steps:
1. Make sure your car is parked in a place where it will be undisturbed.
2. Open the hood. Use your owner’s manual, if necessary, to locate the master cylinder. It should be on the rear driver side of the engine, mounted on the brake booster cylinder.
3. Place a towel under the brake master cylinder to catch the fluid. Disconnect the brake lines from the brake master cylinder with an adjustable wrench and loosen the nuts with a tube wrench.
4. Now remove the mounting bolts which secure the brake master cylinder to the brake booster cylinder with the wrench or a ratchet and socket.
5. Lift the brake master cylinder and place it on a clean table or workbench.
6. Plug the brake line openings with pieces of cloth to prevent any contamination.
7. Empty the brake fluid into a plastic container. Then remove the fluid reservoir from the cylinder with a screwdriver.
8. Use snap ring pliers to remove the lock ring which secures the pistons in the brake master cylinder at the back of the assembly.
9. Now remove the retaining ring which secures the top valve.
10. Tap the master cylinder on the surface of the table in order to slide the seals, pistons, and valve assembly out of the body of the brake master cylinder. Keep all of the parts organized once you get them out so you know how to reassemble them.
11. Replace the bad seals with the new ones.
12. Put everything back in the body of the master cylinder exactly the way it was before you took it out.
13. Bleed the master cylinder.
14. Put the brake master cylinder back in the car. Connect the brake lines with the nuts being very careful not to damage the thread. Reinstall the mounting bolts and tighten everything up.
15. Bleed the brake system and add brake fluid.
16. Check the brake master cylinder for any leaks.
Go to a Car Repair Shop
If you don’t have an OBD2 scanner, you can take your car to a local automotive professional who has one. Most car shops have computerized tools to perform diagnostics on your vehicle. You can also make sure that your brake pads are not eroded to the point that you should not be driving your car. You can prevent an escalating problem by having regular maintenance checks on your vehicle which typically include the brakes.