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

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.

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?

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.

Is the ABS indicator light showing?

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.

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.

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.

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

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!

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.


The above was what he did to resolve the problem and has since not reported back with any problems.

Yes, I read that and have done it with the same outcome, but the problem keeps coming back, and on a more regular basis now. I found a used module on e-bay for A$130, so have bought it and awaiting delivery. Kia said they would fit it for free for stuffing me around for a week (and costing me $2K+ so far)
I thought you may be able to e-mail him and find out if he followed up with the module as he intimated in his last post.

When you replied to this post, he is notified via email and he has since received more than one notification so hope he replies.