My Cummins exhaust brake has not been working for the past couple of weeks, found out today that the belt driven vacuum pump is toast. Cost to replace pump plus rebuild the brake itself, worn parts, is almost $1000.00 CAD including labour. Given that there are many different manufacturers of exhaust brakes I'm turning to the members here for their advice, repair or replace with new. If replace with new which is the best value for money spent. Thanks.