Long time lurker...first time Boxster forum poster....

I have a 2005 Boxster, 33Kmiles, that I bought CPO one year ago. About a month ago I noticed that when I got in the car, before I started the engine, that the brake pedal was rock hard. When I start the car it sinks a bit and feels normal. Driving errands through the day and the pedal always feels normal when I start the car. If it sits for more than a few days, firm brake pedal before starting the car.

I took it in to the dealer for fluid change, and they flushed the brake system and couldn't find anything. I had then look again and they checked everything (or so they say) and can't find a problem.

The service writer looks at me like I'm crazy. The brake pedal feels different than when I bought the car, feels much different than any other car I have (including my Carrera).

Any other suggestions?

 

I noticed that when I got in the car, before I started the engine, that the brake pedal was rock hard. When I start the car it sinks a bit and feels normal. Driving errands through the day and the pedal always feels normal when I start the car. If it sits for more than a few days, firm brake pedal before starting the car.

THIS MY FRIEND IS NORMAL.

 

This happens to my 05 987 as well. I posted about it over at RennTech.org and Loren suggested a brake fluid flush. However, I never had it done because after the initial start it seems to be fine.

Jason

 

cvazquez is right. when the car sits for a long time, the vacuum brake booster will lose its vacuum. when you start the car, it will come back.

try this in ANY modern vehicle: turn the car off. pump the brake pedal several times. it will get very hard. now, while pressing the brake, start the car. the pedal will sink. totally normal.

 

I have noticed the same on nearly all my cars that sit for more than a 1 week.

 

Regardless if after the initial start the brake pedal feels fine, Loren is right. Porsche calls for a brake fluid flush/bleed every 2 years for these cars and your 2005 is 2 of these brake fluid flush/bleed services behind.

Sincerely,

Macster.

 

Thanks for the info. I've gotten all of my scheduled maintenance done on time. Is the brake fluid flush/bleed a part of the normal maintenance schedule or is this something I have to ask for specifically?

Thanks,
Jason

 

Yes.. its in the manual as an item that should be checked. Of course, knowing yourself when its time to change it is even better. For a small onetime investment, you can do this work yourself, learn more about your car and in the long run, save some $$ by doing it yourself.

 

I would disagree that this is normal. I understand how the vac assist works, and yes, I've done the experiment where you pump the brakes with the engine not running and the pedal gets firm.

My 07 Carrera doesn't do this. Neither do any of the cars I own, including ones that may sit for 2 mos between drives.

The Boxster did not do this when I first got it.

 

what you're experiencing is smply loss of vacuum from the brake booster over time. If its not affecting your braking, I personally am not that concerned about it. If you're worried, check the brake booster and its vacuum lines. You have a leak somewhere.

 

All our cars do the same thing.