[Mgia0055]

I've read a number of articles on theses issues but haven't been able to chase down the source of my problems. I know this my be a rehash...

Car's a 2007 saab 9-3 aero convertible, automatic with 77k miles. Just passed this years inspection.

Issue 1: hard brake pedal at startup when car has been sitting overnight. Resolves itself after a few minutes running. I've tested the brake booster by pumping the brakes before starting, pedal becomes firm, start vehicle and pedal softens and pushes in. I think that indicates it's ok. I've already replaced a broken Brake Booster Vacuum Hose (w/ Check Valve). Problem continues.

Issue 2: rough idle at start. It's very slight when the temp is cool and a bit more noticeable at startup when it's very hot out. I'm assuming it's a coil issue but I've read it could be related to a vac leak. Previously it was running rough under load during acceleration, which lead me to find and replace the brake booster vac hose. Oh and I also replaced the spark plugs a few months ago based on another troubleshooting article. No noticible improvement. That was before the vac hose replacement.

Based on my pressure test, would it appear that a vac leak is to blame?
Suggestions for tackling these items ?

Thanks in advance.

 

[aerojon]

check the electric vac pump is running at start up,FR side by the headlamp..

 

[Mgia0055]

Aerojon, thanks for the suggestion. The vac pump is not running. I pulled the vac line and it did not turn on. I also checked that there's power to the sensor and tried jumping the wires. How do I access the vac pump, from under the car?

 

[Mgia0055]

Source of problem with the brake pedal found. Corrosion of the vacuum pump. Thanks for your help.