my first encounter of a defect water pump was driving into San Francisco. Signs: dramatic vacuum loss, power brakes gone etc. In most cases, however, the vacuum pump can be repaired by taking it apart and changing the rubber parts out, they tend to wear out first. A simple kit is available at www.************************, anyway, a simple garage did this for me in San Franicsco. At about 200k miles, it went out again, the brake booster was pulling oil, This time, the pump got replaced completely