2003 Kia Rio sticking Brakes

AMANDAHEDGES

MEMBER
2003 KIA RIO
4 CYL
2WD
AUTOMATIC
170,000 MILES

Hi I have a 2003 kia rio and the driver side brake keeps sticking I got the car with the brake stuck so I replaced the caliper the rotor the pads and the flex hose and they still keep sticking. Every time I get in the car for the first time the brakes are fine and after I drive it for a few miles the brake pedal gets harder to push and as the brake start getting stuck tell it's fully stuck and I can't even push the pedal down anymore and I don't know what it can be so any help would be greatly appreciated thanks Amanda

1 Reply

CARADIODOC

MECHANIC
33,744 POSTS

In your reply, please use punctuation, otherwise that huge sentence can be read multiple ways, and you know I'm going to read it wrong. The flex hose is the most likely suspect, but since that has been replaced already, I'm worried that the next most likely cause is brake fluid contaminated with a petroleum product. The next time this happens, stop on a slight incline, shift to neutral, place a block about a foot downhill of one tire so you won't look funny chasing after the vehicle, then use a line wrench to loosen the steel lines at the master cylinder. If brake fluid spurts out and the brake releases, there's three possible causes. The brake light switch could be misadjusted and is holding the brake pedal down an inch or two, the power booster may have been replaced and has an adjustable push rod that is adjusted too long, or the brake fluid has engine oil, transmission fluid, power steering fluid, or penetrating oil in it. That is going to be a real expensive repair.

A quick test for the first two causes is to loosen the mounting nuts where the master cylinder bolts to the power booster. Slide the master cylinder away from the booster about 1/8". If the brake releases, contaminated brake fluid is no longer the main suspect.