08 MC Automatic - 122k miles. Brakes work very well, the pedal feels right, and the braking and brake fluid are what I'd expect. However, if I let the car sit for a couple of days, the brake pedal is hard when I push it in to start the car. Once started, the feel is back. What it appears to be is that the vacuum has leaked out somewhere during the multi-day downtime. It's the same feeling you get if you repeatdly pump the brakes after you've shut the car down -harder pedal, less vacuum assist.

Anyone know of any known issues that might be causing this, aside from tracking down the vacuum lines generally?

thx- andy

 

It's not uncommon for vacuum to leak down over the course of a few days. I wouldn't worry about it, unless it gets noticeably worse.

 

Could also be a problem with the master cylinder.

 

Totally normal....
If you want...
Shut the car off....
Then pump the pedal a couple times....once the stored vacume is used up...the pedal will e very hard...
Then restart the car....and it will be normal in a few seconds....
Most every car with power brakes ever built has this behavior....

 

Thanks, everyone. Yea, I know about the vacuum loss after pumping when the car is off. It's just that on the Mini it seems the vacuum seems to fade after a few days (without pumping) vs other cars where the vacuum sticks around. given that it returns to normal once you start the car, I won't fret about it. Just was curious if the mini's were different in this regard.

andy

 

Naww...
It fades away on most every car....especially as they age. Things wear...and seals are no longer perfect. I would consider it just part of owning a car that is a bit past its prime....after all, at 120k+
The car is likely more than half "used up" and on the long downhill slide to "hoopty" status....
Not saying it is junk....just saying as stuff ages, it becomes imperfect, but perfectly usable and safe to use as intended. Watch it for changes, but should be fine.