While driving the front brakes seize, but they will randomly unseize?

JLUNDO

MEMBER
2009 KIA RIO
1.6L
4 CYL
2WD
AUTOMATIC
96,000 MILES

Hello, I have a brake issue with my vehicle listed above LX model. The front two brakes get seized up and stuck after 5 miles, and the brake pedal becomes very hard. It makes it hard to accelerate but will randomly fix itself while driving. I have already replaced both front calipers, pads, hoses, and wheel bearings. It will undo itself if I park on a downhill slope, and I can hear dripping/knocking, and the caliper slowly releases.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,960 POSTS

Yep, this can happen for one of two reasons, either you have a brake booster that is going bad and won't allow the brake master to return fully or the brake master cylinder is going bad and not fully returning. You can confirm the issue by loosening the brake master mounting nuts about 3 turns and if the front wheel starts to turn again you have found the problem. Please go over this guide to see what I am talking about, and I have included how to change the parts out as well in the images below.

https://www.2carpros.com/articles/a-comprehensive-guide-to-fixing-automotive-brakes-locking-up

and

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

This video will show you how to bleed the master:

https://youtu.be/WDxvEQrMkBg?si=ntvLC3ILsXUCgGpm

If it is not obvious, I would do the brake master first.
Check out the images (below). Please upload pictures or videos in your response of the problem so we can see what's going on.

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