Brakes feel squishy

My brakes are squishy when I first start my car. It feels like there is air in the line. The brake fluid might be leaking as well.
Experienced mechanics share their insights in answering this question :
You are correct that excessive pedal travel can be caused by air entering the brake system. However, unless there is a leak or the system has recently been serviced, air should not have entered the system. There could be a hydraulic leak somewhere or the master cylinder could be leaking internally. Brakes are a safety concern so I suggest you have your vehicle inspected as soon as possible. A qualified mechanic will be able to diagnose and repair your brakes to have you safely back on the road.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

Air in the brake line(s) is the most common cause of a soft/spongy brake pedal. If air gets into the brake lines, it can prevent brake fluid from flowing properly, causing the brake pedal to feel spongy or soft. If the brakes are soft or spongy, this is a good time to change or flush the brake fluid.
Brake fluid converts the pressure on the brake pedal into braking force to bring a vehicle to a stop. However, if you have a brake fluid leak, the low brake fluid will result in spongy brakes that sink to the floor.
Brakes feel spongy

As the problem with the vacuum brake booster check valve increases, air bubbles will progressively move down the brake lines and to the brakes themselves. In this case, the air that is supposed to be removed by the check valve enters the master cylinder and then into the brake lines.

No. If your brake pedal feels spongy, your vehicle is not safe to drive. Identify and repair the underlying issue as quickly as possible. Spongy brakes are common and dangerous problems for any vehicle and indicative of a deeper problem.
The classic symptom of a failing master cylinder is a brake pedal that “dives” or sinks slowly to the floor while pedal pressure is being applied. Another sign to look out for is any leaks around the master cylinder. If a seal is worn out, it may leak past the seal and onto the pushrod that attaches to the brake pedal.
If they`re spongy after bleeding, you need to bleed them again. If you forgot to top up the fluid in the reservoir to replace the fluid you drained out, you would have introduced air into the top of the system so you`ll need to drain ALL of the fluid to get rid of the air.
As your brake fluid ages or becomes dirty, it will affect how well your brake pads function. You may hear a squealing, grinding, or another odd sound coming from your brakes. Another telltale sign is your brakes take slightly longer to bring you to a complete stop.
In the Car: With the brake system bled, pump the brakes a few times and hold. The brake pedal should be firm. If the brake pedal is spongy, this could indicate air remaining in the lines or a mechanical problem, such as a sticking brake caliper slider.
The easiest way to diagnose this problem is to pump the brake pedal gently a few times. In doing so, the pedal should become firmer with each gentle press of the pedal. If it does, then the necessary answer is bleeding the brakes.
If you suspect your brake fluid is leaking, do not attempt to drive it. Look under your hood and check the brake fluid reservoir. An empty reservoir means that your brakes have been leaking for a while. Have your vehicle towed to your mechanic for a professional repair.
Leaks might not just let fluid out, they could also let air in. The only way to be sure your system doesn`t have an air bubble is to bleed your brakes after repairing the leak. If you`re replacing worn brake pads, which can cause air to enter the master cylinder.
One of the most common reasons for your brakes touching the floor would be an issue with your brake fluid. Your fluid being low or air reaching the brake line will prevent the fluid from flowing properly, resulting in a spongy pedal. A bad brake booster is another common cause for a malfunctioning pedal.
YOU SHOULD REPLACE BRAKE FLUID EVERY FEW YEARS

And the best way to find out how often to change brake fluid is to follow your manufacturer`s recommendations. Some manufacturers say you should replace your brake fluid every two years. Others recommend every three years, or every 45,000 miles.

One of the most common reasons for your brakes touching the floor would be an issue with your brake fluid. Your fluid being low or air reaching the brake line will prevent the fluid from flowing properly, resulting in a spongy pedal. A bad brake booster is another common cause for a malfunctioning pedal.
Low brake fluid will cause air to fill the gaps in your brake line—leading to soft brakes. Spongy brake pedals can be both terrifying and dangerous—especially if you do not get them serviced at the first sign of an issue.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

I replaced the brake light switch. Gear lever unlocked because it had locked. Now the brakes feel hard.
ANSWER : Hi, thanks for writing in. You need to check the brake switch install adjustment. You may have the switch adjusted too tight and it is holding the the brake pedal partly down. This will cause the brake master cylinder to not release the brakes when you let off the pedal. Readjust the switch away from the pedal until you feel some free play again in the pedal. This should fix the problem. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

Read Full Q/A … : Brakes feel squishy

Low brake pedal and anti-lock brakes are not kicking in.
ANSWER : The brake pedal is working to stop the vehicle, but there may be air in the controller unit causing the ABS brakes to not function. I recommend bleeding the brake system from the farthest location from the master cylinder to the master cylinder including the ABS unit. If the brakes are still spongy after a full bleed, then the controller will need to be replaced. If you need further assistance with your brake pedal being spongy, then seek out a professional, such as one from Your Mechanic, to help you.

Read Full Q/A … : Brakes feel squishy

When I put my foot on the brake my back left brake light goes off, when I take it off the brake the brake light comes on
ANSWER : I would suggest trying to disconnect and reconnect the wiring to the rear lights. I have seen these older Toyota vehicles rear lighting short out on the lights themselves due to the way the light circuit was made on the lamp housing. Look at the housing circuit on the light to see if one is touching another, and that could tell you why it is malfunctioning. There could also be a problem with the brake light switch. If you are not comfortable dealing with wires, I recommend getting in touch with a certified mechanic who can look at your brake light issue for you to see what’s going on.

Read Full Q/A … : Brakes feel squishy

EPC light on 2004 Jetta. Code said brake switch faulty, but brakes lights worked. Replaced brake switch, now no brake lights.
ANSWER : Hi there. The first thing that pops in my mind beyond of what you have listed is perhaps the electrical harness attached to the brake switch. Perhaps the harness itself is damaged or you have an exposed wire, loose ground wire somewhere. You might want to have a professional mobile mechanic come to your location and complete a brake lights not working inspection to help you diagnose this issue.

Read Full Q/A … : Brakes feel squishy

Brake sensor is to sensitive causing brakes to flicker while driving. 2005 Mercury Montego
ANSWER : Hi there – your brake light switch needs a minor adjustment. It is adjusted too "tight" or close to the brake pedal lever, or possibly has failed. Adjusting/replacing it will eliminate this flickering problem. I recommend a brake light isn’t working inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

Read Full Q/A … : Brakes feel squishy

Supportive bar attached to brake pedal interrupts proper braking process
ANSWER : It’s possible to have someone alter the brake pedal or adapt a brake pedal from a different vehicle. You may call around to some customization shops to see if anyone is interested in taking on the project. But first, I would try reaching out to the selling dealer with your concern – especially since it is a new model. Good luck.

Read Full Q/A … : Brakes feel squishy

Brake pads replaced but still feel soft
ANSWER : It sounds like your 2006 Freestar does have a legitimate brake issue and the mechanics you are currently going to have not identified it. You need to have confidence that your brakes are "working as designed" and will stop your vehicle! You may want to speak with management and give them one more try at making it right. Diagnosing and repairing brakes should be a fairly easy job for a trained mechanic. Make sure that you are using top quality parts and are following correct procedures. If you do not feel comfortable going back to the same shop, have a certified mechanic, such as one from YourMechanic, come to your home or office to diagnose and repair your brake issue.

Read Full Q/A … : Brakes feel squishy

I feel a shimmy on the brake pedal a bit when I brake at high speeds. Does this mean the brakes should be changed?
ANSWER : Usually when the steering wheel shakes during braking, it is caused by a warped rotor or drum. It could also be that there is fluid leaking onto the brakes and it causes them to grab intermittently. A brake inspection will tell you if it is a leak. There are other possible causes for a brake vibration, but an inspection will be the best bet. If you would like, this inspection can be performed by a certified technician from YourMechanic, who can come to your home or place of business at the convenience of your schedule.

Read Full Q/A … : Brakes feel squishy