My problems and the symptoms

I just got my brakes chcked out and got new brake hoses and cylinders on both front wheels. Now, I have a weird noise coming out of the right rear wheel. My brake light is on, yet I can't check the brake fluid, cuz my damn hood won't open. Anyway, I was pushing down on the car with the parking brake off and it was making a swischy noise. I thoght maybe it was the shock or strut (I havewn't any idea of the difference, I'm learning here), but when I put the parking brake on, it no longer made the noise when I pushed down. My friend thinks it's a cracked cylinder and that makes sense due to a loss of brake fluid previously, but as stated I have no idea about cars.