Brake pedal fades to floor with engine running

Tiny
P JAMES
  • MEMBER
  • 2009 KIA RIO
  • 1.8L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 15,500 MILES
Rear shoes and hardware have been replaced and master cylinder replaced. Still have same problem. Adjustment and bleeding performed. Pedal will pump up but then fade to floor.
Saturday, May 16th, 2020 AT 5:56 PM

5 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,854 POSTS
Hi,

If the brakes pump up and then slowly go to the floor, either you have a leak or another bad master cylinder. Does the fluid go low?

Take a look through this link and let me know if it helps:

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

Let me know. Remember, this is a sealed system. For the pedal to go to the floor, there has to be a leak or issue with the master cylinder.

Take care,
Joe
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Saturday, May 16th, 2020 AT 11:22 PM
Tiny
P JAMES
  • MEMBER
  • 2 POSTS
  • 2009 KIA RIO
  • 1.8L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
Brake pedal fades to the floor.
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Monday, May 18th, 2020 AT 1:20 PM (Merged)
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
The brake going to the floor is normally a sign of a leak or air in the system. Have you done any repairs on this vehicle recently?

Here is a guide that will help explain this:

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

Basically we need to look for external leaks and then bleed the brakes assuming the reservoir is full.

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

I suspect we are dealing with a master cylinder issue that may have an internal leak if you don't find any leaks and have not made any repairs.

Let me know and we can go from there. Thanks
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Monday, May 18th, 2020 AT 1:20 PM (Merged)
Tiny
P JAMES
  • MEMBER
  • 2 POSTS
I found the problem. I dissembled front brakes and found sliders seized freed up sliders and brakes are perfect now. Thanks for your help.
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Saturday, June 6th, 2020 AT 12:50 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 44,449 POSTS
KASEKENNY1 is one of our best! Nice work, we are here to help, please use 2CarPros anytime.
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Saturday, June 6th, 2020 AT 12:50 PM

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