The other day, I had the following work done by a mechanic (non-dealer):

1. New Nissam OEM brake pads all-around
2. New Nissan OEM front rotors
3. Machined Nissan OEM rear rotors
4. New caliper seals for rears because I popped out the pistons (tried to DIY)
5. Flushed entire system (was completely drained of fluid) for same reason as above (sigh)

The new brakes feel kinda weak. The pedal isn't nearly as stiff as it used to be. The car brakes fine and I stress-tested it on a wet road last night. Tried slamming the brakes really hard and ABS works, etc, but you have to push the pedal a lot harder to get the same result. Also, I think that while driving, I can hear a very slight metallic noise from the brakes. Its the same noise a knife makes when it's being chiseled against a stone, but it's very hard to hear and would be impossible to hear if the AC was on or something. What should I do?

 

if you drained the entire brake system of fluid, there might still be air in it. should always flush using new fluid to push out the old one. tap the calipers with a rubber mallet and the master cylinder and bleed the brakes again then do a bed in process.

 

+1 on air still in the system. You have Brembos???

 

Usually there is a tool that will cycle the abs pump/valves to get the air out of the abs unit, then you have to rebleed the rest of the system. Other cause could be that they didnt bleed the master cylinder before the rest of the system. Take it back and tell them to bleed it properly, or bring it to nissan and let them use their tools.

 

Tapping of calipers and other components is important ---also on a complete loss, driving awhile will knock that air loose also ---Gravity bleed them again

 

+1 on rebleeding.

That's just a brake fluid problem.

 

Dont forget to bed in the system to get the most out of the parts. Until there is a good pad transfer layer to increase the bite of the system the pedal will have a bit of a dead feel and require more force to realize work. With ABS working and relatively firm pedal it doesnt sound like you have any air in the system.

Our recommended bed in procedure is on the aggressive side so if you are doing it on factory pads, I would recommend cutting the amount of stops from 10 to about 8 so you dont overheat them. Performance street pads can handle the heat of the full 10 stops. Full instructions here: http://www.stoptech.com/tech_info/wp_bedinstock.shtml

-Erik-