Hydro Boost brakes. I had heard of them before and I knew they existed, but I didn't understand how they balance you on the brink of disaster should something go wrong.
My friend's girlfriend was driving his 2000 Savanna today, when apparently the power steering pump failed. Not only did she lose power assist in the steering, but the brake pedal sank to the floor and became immovable. Basically, no steering or brakes. Fortunately all she did was sideswipe a parked car, but a few minutes before that she was on the freeway.
My buddy went to go 'rescue' her, because she couldn't drive the van anymore. He figured she was just weak (because she's a girl) and that he'd be able to muscle the van home. But to his surprise it took everything he had to turn the wheel even a couple of inches while the van was rolling. And there really are no brakes. Even when standing on the pedal, there's no usable stopping power. Fluid level is good, belt is intact, no external leaks, pump turns when the engine does, but no power assist in anything.
I realize that systems fail and these things happen, but it seems like a pretty bad idea to have steering AND braking power so interrelated. Pump failures are probably rare, but tossing a belt usually isn't, and it seems like that could have had the same result.
My buddy's van is wrecked, and now he'll have an insurance situation for the other car that got damaged. He's glad his girlfriend is alright, and nobody got seriously hurt, but sheesh.
-J