dewdo, I'm sorry to here of your exhaust brake troubles and would agree to the other posts on this subject that if you could operate the brake once a day, by simply turning it on and off, then the butterfly should stay free for an indefinate time.
The inheritant problem with all exhaust brakes is carbon build up and as you know diesels can sure pound out the soot when they get ornery

so if you can keep operating it every day the soot should not build up as much.
As to your problem, we will see whats up when the brake gets to BD and see what actually failed.
But, fear not good sir, because as in life, there is always the possibility of "extenuating circumstances" and we at BD do NOT adhere to a strict written 'rule of law' where warranty applies. BD is in the exhaust brake business because we know brakes and have been a leader in the exhaust brake manufacturing and development for many years.
I look forward to seeing you next week and I'm confident that BD and yourself will come up with a mutually benefitial conclusion to this matter.
Vic Daku
BD Engine Brake Inc
Warranty / Product Support
PS: We Canadians also feel compelled to voice our disgust with the unthinkable and despicable acts of Sept 11 and feel that the attacks on the US were in fact an attack on NORTH AMERICA and our way of life... . GOD BLESS AMERICA and all the souls affected by the terrorist cancer that has infected the world.
PPS: Sorry about the long post, not bad for a guy who failed Grade 10 english 3 years in a row
