Hi all,

This is my first time posting to this forum! I'm here to get some help on the issues with my 2003 s40.

Just like many other s40's, the car has no power brakes when engine's cold. The issue's been there since I bought the car as used 3 years ago, and I thought this is normal as the brakes work fine once the engine's warm. Yet, brakes work fine sometimes even when engine's cold.

Recently the car started to take longer cranking time before it starts up. (Not all the time though.) My first shot was to replace 7-year old battery. The car starts up smoother but it still does that "slow start-up." I would say it does that once every 4 times. At the same time, the car would have rough idle when engine's cold.

I know this could be failing brake vacuum pump & fuel pressure regulator.

My question is:

1. How do I test if the car has a failing pump? Could the power brake issue be something else?

2. I depressed the brake with key off so that all residual vacuum is used, and turned ignition on - the pump runs. Then I depressed the brake with ignition on; the pedal would get hardened. Shouldn't the pump run to compensate that?

3. Could failing vacuum pump cause rough idle and slow start? or would that be totally different issue like failing fuel pressure regulator?

Thank you for reading...!