Recently I replaced my rack and pinion to fix some noise from my steering column. It solves my problem but it also introduces a new problem. Ever since I replaced my rack and pinion, I can hear high pitch hissing noise(sounds like ssssss) when my car almost stops after I apply the brake. The high pitch noise sounds from my front right wheel. I never heard such noise before. Does it have something to with my new rack and pinion? Is it possible when the dealer replaced my rack and pinion, they screwed up with my brake?
forget to mention, the brake works fine. The high pitch hissing noise is only heard when I apply the brake and the car runs at low speed like in the parking lot.
Right before I replaced the rack and pinion, I just pass the annual inspection. No problem was found in brake system then

 

might still have some air trapped in the p/s system? turn the wheel all the way to the left and right without hitting the stops a few times when the eng cold and again when hot, check the fluid before starting to make sure your not leaking in some unseen spot. check fluid after too.

sounds like you might have a leak in the brake vacum booster and or hose (big round thing behinde the brake fluid resvr). the hose is cheap to replace at any parts store, i'd start there first. good luck.

 

Thanks for the reply.
What is the typical cost for reparing brake vaccum booster?

 

if it's just the vaccuum hose the cost is around $10-20.

 

I got my car checked. It was the rotors. There were too thin, so there was vibration and it made high pitch sound