Having some weird braking problems in my 2003 F350 6.0, 160k miles...

So I have noticed my brakes have been a little flaky. After checking them out I bled the front brakes just as a precaution. I topped off my brake fluid - BUT - I grabbed the wrong bottle and ended up putting about a cup of power steering fluid in by mistake (the STP bottles look the same)

Now today, about a month since putting the brake fluid in, my brakes are working sporadically. What happens is I start to brake, the brakes seem fine for a few seconds, and then the pedal drops to the floor. One time, the brakes actually locked up but after tapping the pedal they released. I am not losing fluid from anywhere and there is no indication that it is a caliper.

Could this be the master cylinder? Do you think that little bit of power steering fluid coiuld be causing the problem. I'm not sure how different the properties are between the two. Any help would be appreciated.

Thank

 

Did you completely flush the system after you found your mistake. By complete I mean front and rear brakes. If not try it. You could go thru 2 to 3 qts. but it is worth it. If that doesn't help then the p.s. fluid has probably degraded the seals in the master cylinder and replacement is next. You will have to flush the entire system anyway before the p.s. fluid attacks your caliper piston seals if it hasn't already. Start with the full flush 1st and go from there.

 

Complete flush mean getting it out of the ABS .... that takes a bit of work.