My brakes are real mushy when I press them; while driving they become hard. on 1997 Toyota Land Cruiser

I am having a problem when I press my brake pad. There are times when they are mushy (When I haven't driven for a hour or so) If I experience frequent stops, then they may become hard at the next stopping point and all I have to do is barely touch my brakes and they will stop the truck. I am noticing a vibration in my steering wheel when my brakes are hard as if the calipers are not retracting like they should. During the times when my brakes feel hard my truck seems as though my brakes are engaged when I am driving and it appears to want to stop the truck. I sometimes smell a burning odor and see smoke coming from my front passenger brakes. The smoke doesn't occur daily but everything else is a daily occurrence.

by in Arlington, TX on October 17, 2012
2 answers 2 comments
ANSWER by on October 18, 2012
sounds like you have either a caliper seizing up or the master cylinder is going
COMMENT by on October 18, 2012
Thanks for the response! How can you tell which one is the real problem?
ANSWER by on October 18, 2012
i own 4 toyotas;front calipers are 4 piston design,chances are at least one or two are sticky.if r/s caliper is bad change both!
COMMENT by on October 18, 2012
Thanks for your response to my issue. I will check the calipers.