A FEW MONTHS AGO THE BRAKES AT TIMES WOULD ALL ...

  • Tiny
  • kha325
  • 2007 Kia Sorento
  • 107,000 miles

A few months ago the brakes at times would all of a sudden start to feel real spongy and the pedal would goto the floor but it would stop. Turning the car on and off would usually fix this. After about a month or so it started doing this full time. The dealer recommeded a rear brake change. I changed the pads and rotors myself but it still had the problem. Dealer then said it's the Master Cylinder. Ok, I changed the Master Cylinder and got the brakes bled. Same issue. Dealer of course says it's still a faulty MC. When applying the brake pedal it initially feels like it's grabbing but then stops braking till you apply more force. No codes or lights either.

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Wednesday, October 31st, 2012 AT 5:20 PM

13 Replies

  • Tiny
  • KHLow2008
  • Expert
  • 41,997 posts

If you are sure restarting the engine fixes the problem, the ABS system needs to be checked.

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Wednesday, October 31st, 2012 AT 5:24 PM
  • Tiny
  • kha325
  • Member

At this point restarting does not fix it. Really feels like the brakes are starting to grab in the first inch of pedal, then they just go soft.

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Thursday, November 1st, 2012 AT 2:51 AM
  • Tiny
  • KHLow2008
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  • 41,997 posts

When you mean soft, does it goes to the floor as before replacement of the master cylinder?

Were the front brakes checked? Are you losing brake fluids?

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Thursday, November 1st, 2012 AT 5:27 PM
  • Tiny
  • kha325
  • Member

They almost goto the floor. Same exact travel as before the replacement MC. The front brakes are fine and have plenty of wear left. Not losing brake fluid either. I was thinking possible speed sensor issue but it does this all the time including sully stopped.

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Thursday, November 1st, 2012 AT 5:42 PM
  • Tiny
  • KHLow2008
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  • 41,997 posts

Is the ABS indicator light showing?

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Thursday, November 1st, 2012 AT 5:52 PM
  • Tiny
  • kha325
  • Member

The abs light was on briefly a few months back possibly when this started but has not been on since. I checked the fuses for the abs which were ok.

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Thursday, November 1st, 2012 AT 6:28 PM
  • Tiny
  • KHLow2008
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  • 41,997 posts

When the ABS indicator light come on, it means an error had been detected. Even though the light has gone off, trouble codes would still be stored in the memory and I would suggest retrieving the code and see what it says.

Since vehicle is equipped with ABS, look for a sandy stretch of road and while driving, perform sudden brakings to test if the ABS works. This might also solve the soft pedal pressure. Ensure the road is clear of other road users to avoid accidents. You need not be travelling at high speeds, just enough to make the ABS work when wheels locks.

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Thursday, November 1st, 2012 AT 7:30 PM
  • Tiny
  • kha325
  • Member

Tried it. Brakes are back to normal. I guess there is some kind of problem with ABS control module but at least I can get it working if it does it again. Dealer could not figure this out. Thank You for your help.

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Friday, November 2nd, 2012 AT 2:22 PM
  • Tiny
  • KHLow2008
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  • 41,997 posts

You're welcome. Glad to know you have fixed the problem.

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Friday, November 2nd, 2012 AT 2:43 PM
  • Tiny
  • woffking
  • Member

I have the same model car in Australia, and have had exactly the same symptoms as described above. My local Kia dealer has had the car for the last week trying to determine what the problem is. They have been in touch with the gurus at Kia Australia, but have not been able to solve the problem. So far they have replaced the Master cylinder ($600) and all the rotors and pads, both front and rear ($1500+). They have continuously bled the system to no avail. So far the cost is up to $2K and climbing, with no answers in sight. Next option is to change the ABS module at a cost of almost $3K with labour, and no guarantees that this will fix the issue. Can you contact the originator of the above (kha325) to see what the outcome of his investigation is and let me know. I am loathe to spend a further 3K if it is something a lot simpler!

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Tuesday, July 9th, 2013 AT 2:48 AM

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