2007 Kia Sorento Q&A

2007 Kia Sorento Question: brake shimmy

replaced the front pads twice & the rotors once i get a harder shimmy at about 1/2 brake pedal and worse the higher the speed. hard brake or light brake they feel almost perfect I do have a high spot blueing on the rotor not sure if it's the calipars hanging (4 piston type) or maybe the rubber brake hoses? those are the only other things i can think of causing the problem. I have no problems stopping no pulling just the annoying shimmimg at normal braking the pads look evenly worn just the rotors have a 2" blue/high spot on both the originals and the new replacement rotors. I am stumped but don't want to buy new calipars on a hunch just yet without a 2nd opinion, thanks -
Answer 1
I would question the quality of the brake rotors. They are definitely the cause of your shimmy. Blue spots can indicate overheating - I would not suspect calipers or hoses unless the pistons could be verified as difficult to compress. Perhaps have a look to make sure the rear brakes are performing up to par. Granted - they are rear disc brakes, and should be pretty much trouble free also. Make sure all your caliper slides are lubed and not binding. -
Comment 1
that's what I was thinking I had 4 piston on one of my other cars and never had a problem nor ever heard issues with 4 piston cals. the originals started about 35,000 and was sure it was the rotors even though they are vented I always thought they were too weak for the truck. I may just upgrade to a good H.P. rotor cause I drive a mtn.to work and high miles so. the rears are good the first thing I checked both the 1st time and when it started with the new pads & rotors. Thanks Dave -
Comment 2
If you drive a mountain to work - indeed it may just be ...normal operating conditions that cause your overheating. Try downshifting to a lower gear instead of using the brakes as much. You've got the right idea, for sure. -