Brakes not working

Tiny
DWBOMEILL
  • MEMBER
  • 2005 PONTIAC G6
  • 3.2L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 130 MILES
First the pedal would stop about 1/3 down and lock in place but but not stop the car. Then after a few days had to use the car and pressed on brake pedal to stop at a stop sign and the pedal stop at 1/3 then popped and then it hit the floor and now the system has no "like 0% stopping". Please help!
Sunday, August 8th, 2021 AT 12:22 AM

7 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning,

I would check the system for any leaks. It sounds like you either broke a brake line or the master cylinder has failed and needs to be replaced.

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

You will need to bench bleed the master cylinder before installing it.

https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system

You will have to have an advanced scan tool to bleed the system as the ABS has to be bled as part of the bleeding process.

Roy
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Sunday, August 8th, 2021 AT 8:38 AM
Tiny
DWBOMEILL
  • MEMBER
  • 5 POSTS
Well, reserve is full no leaks I can see. I look at each wheel no signs of brake fluid and master cylinder is clean. As for ABS mod. Obd2 scanner said lost com to ABS 1 time but no ABS light has never been on, and pads are good like 50% left. Pedal just started to get hard then pedal would lock about half way down but only apply about 35% braking power then after 3 days I hit brakes it locked at 25% and then I felt a "pop" and went to floor with 0% braking?
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Monday, August 9th, 2021 AT 6:55 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
You have a failed master cylinder. The internal seals have failed.

Roy
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Monday, August 9th, 2021 AT 7:17 AM
Tiny
DWBOMEILL
  • MEMBER
  • 5 POSTS
Thank you. Roy I will look in to it, also if I do replace it then as for bleeding I have a scan tool that does ABS and the car has a auto bleed built in with a obd2 will that be adequate or should I do it old school and have a friend just pump and hold as I bleed each wheel starting from passenger rear to driver rear to passenger front to driver front?
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Monday, August 9th, 2021 AT 7:54 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Okay, you will bleed the ABS module first. Then you will bleed using a second person for the rest of the system

You are welcome.

Always glad to help.

Roy
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Monday, August 9th, 2021 AT 7:59 AM
Tiny
DWBOMEILL
  • MEMBER
  • 5 POSTS
Roy, please help. I was removing and replacing master cylinder and both bolts removed studs half way now I have got one off by using a 6mm sock it on stud and 13 on nut but number 2 is all most impossible to move on stud?
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Thursday, August 12th, 2021 AT 6:45 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Can you please upload some pictures of what you see?

Roy
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Thursday, August 12th, 2021 AT 6:50 AM

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