What is the reason that car makes hissing noise when you step on the gas pedal?

Question

Recently I changed the rear brakes and rotors and I am 95% sure that since then when I step on gas pedal I am hearing a hissing noise from left rear wheel side. Noise is fine and high pitch/sort of squeaky - like when steel and coin rub together. As long as I put pressure on gas pedal I hear the noise and when I release pressure there is no noise. What can I suspect?

Answer 1

remove your wheel and vissually check that nothing is loose what brand parts did you purchase and from where?? what year and make vehicle??