I have this wierd thing going on where my brake pedal is very stiff/hard to depress. I have heard of the classic brake booster problem, but the wierd thing is it only acts up during cold weather. I'm from southern California, so cold means around 50 deg or cooler. For instance, every early morning when I leave for work my pedal is stiff, and when I depress it I have no stopping power. I know because the vehicle has been in motion and it won't stop! This lasts for about a minute and then when the engine starts to warm up it goes away. I have noticed this only happens during the winter, not a single problem during the summer, so I have linked this to the cold, and/or when the engine is cold. Kinda scary and a safety issue that needs to be corrected, however, I don't want to get gouged at the dealer and possibly not even get it corrected. I recently took it to a brake shop, pads were about 60%, and they couldn't get it to act up. Has anyone experienced this or heard of this problem? I don' t know wtf is going on; any tips or info would be appreciated!

My 2003 G35 does the same thing (stiff pedal, no brake) on a chilly SoCal morning (I park outside overnight on a nose up incline). The emergency brake works immediately. After the car runs a minute or two I slowly get brake pedal movement and pressure again. I have to push the pedal very hard to have any braking effect. After 5 minutes they work fine. This brake problem happened on rare occasion when it was new, but seems to be doing it more lately. I'm wondering if (hydraulic?) repair would solve the problem or if it's a design flaw? Thanks.