Annoying sound when applying brakes

The master cylinder is likely bad. That is where the problem is most likely coming from. If you don't see any leaks, my suggestion would be to replace the master cylinder. It shouldn't slowly go to the floor and the brake pedal shouldn't go 3/4 of the way down when you brake.

Here is the issue that we need to take into consideration. The brake master cylinder is part of the booster assembly. The system is electronically controlled. As a result, this isn't a simple remove and replace the master cylinder. What I strongly recommend is to have the computer scanned (can-scan). CAN stands for controller area network. Basically, the computers and modules are tied together via a few wires. This type of scan will identify codes regardless of the module storing them. In this case, it's the brake control module.

Here is a link explaining how it's done.

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

I am suggesting this because purchasing a new component is very expensive. This isn't something that I would just arbitrarily tell you to replace without solid proof it is bad. The part alone will likely be between $700.00 and a retail of $1,000.00.

Let me know if that is something you can have done.

Take care,

Joe

Madeline,

If they are working, you should be okay. Just be careful and aware there is a potential issue. If you have a chance, could you let me know what they tell you?

Take care,

Joe

Thanks, Madeline. Be careful and I look forward to hearing from you.

Take care,

Joe

Madeline,

Make sure the parts store has one. This isn't a traditional master cylinder. Also, the person replacing it really should confirm it is the problem before replacing it. It is an expensive part and I wouldn't want you to pay for one and find it isn't the issue.

Based on what you described, it sounds like it is the problem. I just don't want you to waste your money. Just trying to look out for you. LOL

Let me know if you have questions. Also, let me know if you find what you need.

Take care,

Joe

Madeline,

I can't feel comfortable saying that it would be safe. Without having the vehicle in front of me, I can't say. If the pedal is going 3/4 of the way to the floor already, there isn't much left. I can't say it will be safe. I certainly don't want you to have an accident.

Let me know if you have other questions.

Take care,

Joe

Sounds good. If you have a chance, let me know what ultimately takes care of the problem.

Take care, be careful, and let me know.

Joe