If you already have the pump I would put it on. If you did not already have it I would pull the hose from the pump to the brake booster, stick your thumb over it with the engine running and see if it is drawing pretty hard. If it is a company vehicle I would be very cautious running it with a problem with the brakes - an accident and someone finding out what was going on could get expensive for the company.
Dave / Believer45
Dave / Believer45