Help With Breaks!!!

[Socrates]

This is on a 1990 Nissan240sx without ABS.

Sometimes while I am driving the breaks engage on their own without me having pressed down on thepedal. That or the piston is not retracting when I tap on the freeway. I noticed that their was a crack on the boster's vacuum hose and I had nothing else on the freeway but some fuel line hose that was the same diameter. The problem went away but only for a while the brakes later locked again. So I stopped at a autoparts store, but all theyhad was power steering hose I tried that and so far it hasn't happened but that is the same way it felt when I had the fuel line hose on.

Can anybody tell me what is going on with the brakes? Will as soon as I get a vacuum hose identical to the one the cracked fix the problem?

Please Help Me!!!!

I appreciate your help in advance

[KFL]

First I would just get the right hose needed if that doesn't solve the problem then look at brake hardware.Check out the calipers/pads for uneven wear(sticking caliper).