Volvo: Volvo S40 Brake booster house replacement, volvo s40, vacuum pump

Question
i HAVE A FAULTY CHECK VALVE. Volvo SOLD ME HOSE WITH CHECK VALVE (WHOLE THING).
WHAT SHOULD I KNOW PRIOR TO REPLACING ABOVE MENTIONED ITEMS?
ANY SPECIFICS?

Answer
Michael,
The entire vacuum pump has been at fault in many cars. It appears that moisture gets inside and the pump fails. Volvo has made a new pump and changed the location. Maybe your car had the later pump and just needs the hose. Does the hose appear to take the place of the hose you are replacing?  You might even be talking about a hose to the booster from the mainfold. If it looks the same carefully remove the old and replace with the new. As far as I can tell there are not any "tricks" to make installation easier.