We own a '99 Zanzibar which, for at least 3 years, has had intermittent front
end shaking accompanied by brake pedal pulsations when we try to stop plus an
apparent inability to maintain spped. This happens within 15 minutes of a cold
start. If we let the unit sit with engine off for 15 minutes it seems fine for
the rest of the day. Monaco twice directed us to have the Pac brake evaluated:
this resulted in two service calls and replacement of the spring mechanism and
the solonoid to control airflow. The problem persisted. We finally had the
Pacbrake rendered inoperative by removing the air supply. No change. This
Summer we received a recall notice about the Bosch front brake calipers and had
these changed out with no change in the situation. Monaco paid for an engine
evaluation including computer monitering and fuel pressure monitering while
driving. The problem did not occur during this test drive but the mechanic
noticed the brakes were not stopping the unit effectively. We also had the
Allison transmission checked-no problem there. The unit was returned to the
brake service facility; during the test drive their mechanic experienced the
shaking and slowdown and was extremely scared by the event. After a discussion
with Monaco to confirm an impartial observer had experienced the same events,
new rotors and bearings, master cylinder and brake boost were installed.  The
ABS system was tested and was normal. The original problem seems to have been
resolved but is now replaced by a new one. This consists of a thumping sound
coming from the right front wheel well when braking.  There is no obvious
deterioration of braking or tracking.  The front tires and wheels were swapped
with no change. Because the service facility thought the new right front
caliper might be faulty this was replaced.  The thump remains.  We have no
nearby Safari factory facility where we might bring the unit.  According to the
service shop Monaco technical appears baffled by the scenario and they are
rapidly losing interest in persuing a remedy.  Any suggestions would be greatly
appreciated.
Max and Mary Lou Walten