Ok I about had enough wit this Maxima and Brake/Caliper system.. I finally fixed the rattling noise underneath my car which came from a caliper on the rear passenger side which was shaking a few weeks ago. I changed the caliper a few weeks ago. the older one i changed last summer along wit a new brake line. The newer caliper now seems to b changing color like a light brown color which to me indicate they are heating up some way????....... i dont smell no brakes burning but whenever i apply the brakes they feel spongy no bite to it. I changed the rear rotors and brakes last month..can someone tell me what can b the issue. the caliper obviously came grey and i noticed some light brown markings on it (not alot but enough) Please help so I can finnaly put an end to this madness wit this right rear caliper fo good

 

P.S all other calipers on da car is grey

 

Anyone?

 

Best bet, based on what you've described- there may still be air in you brake system. I'd try bleeding the system- flush at least a pint through that caliper.

 

+ 1, then paint them to see if the brown spot appears again.