i’m having problems with my front breaks on a kia spectra 2001 i change calipers, flex hoses and for some reason my front right braks lock up on me after a short time of drivein it and the pedlal gets hard what could it be
check for kinked lines, the rubber line from the chassis to the caliper can also collapse internally. There may be a proportion valve that allows equal pressure to be applied to wheels. You could also have a problem with an ABS unit or master cylinder. Jack the problem wheel off the ground, apply the brakes lock the wheel. If you loosen the bleeder does the wheel free up? If so you have a hydraulic problem. tighten the bleeder and make the wheel lock up again, loosen the brake line connections at the unibody wheret he rubber line and steel line meet, does the wheel free up? if so you problem is between the line you just opened and the master cylinder, if the wheel remains locked the problem is between the the opend line and the wheel. It is a process of elimination. don’t let you master cylinder run out of fluid, and you will need to bleed the brake line when ever you open up a connection.
i have change the proportioning valve, and still locking up,but the funny thing is that only one locks up if it was the master cylinder wouldn’t the pedal sink all the way down i was told that it could be the booster too i have only two more things to replace master cylinder and the booster. so i don’t know what to do.