2003 XC70 - Brake Booster Pump runs too much

[JLK]

I searched the site but could not uncover an answer to this specific question.

I replaced the booster vacuum pump and booster switch as they were burned out. The booster vacuum pump runs but seems to run too much. While I am driving I can hear it. I checked the hoses and they seem fine and can’t uncover a leak. Here is the question. Does this year xc70 have a check valve on the hose that runs from the booster switch back to the boster itself. I searched and found schematics which seem that a check valve is supposed to be on that hose but I cant confirm. This is my sons car that he has at school so I do not know the full service history so not sure if this has been worked on before.

Any thought are appreciated.

[oragex]

Failed brake booster seal at the pedal