I have a W22 chassis and had the brake problem 3 times before they got to the recall. Brake fluid will absorb moisture from the air as soon as it is installed. Moisture will boil when heated enough. You can compress a gas but not a fluid. The original Bosch problem was insufficient clearance for the piston in the caliper. The piston was also subject to absorbing and swelling from the moisture in the brake fluid. When it swelled the piston could not retract and would cause the overheating when the brakes were appliied. After sitting for a half hour it would be OK until the next time. The new calipers have greater clearance for the pistons. I have had no problems since the recall and am very happy with my coach and chassis. They still recommend flushing the brake fluid every 2 years. Mine is to be done next Monday. It takes a quart of fluid and takes about 20 minutes.
