If the car sits overnight first thing in the morning the brake pedal is hard and there are almost no brakes. It feels like the servo soelinoid or something isn't letting vacuum get to the booster. when you drive the boost comes up in just a quarter of a mile or so and is fine the rest of the day. Any thoughts on the first thing to check or how to test the brake servo or .....you fill in the blank ? thanks

 

There is a valve that goes into the front of the booster. It is part of a hard plastic line. The valve usually goes bad.
Also check the relay connections on the vacuum pump motor.

 

on my 2000 s40 this was a recall that the dealer fixed for free. check that first

 

I'm calling the dealer now. thanks

 

no problem. let us know what happens

 

I had the same problem 2 years ago on my 2003 S40. Now the problem is reoccurring AGAIN. I called the dealer and they pulled out the part number/price: 120 USD in Ann Arbor MI (it was 100 bucks 2 years ago). Part Number 30620958. Let me know if your part number matches the one that solved my problem the first time.