Coolant bottles are not designed to break. If excess pressure builds in the cooling system for whatever reason (overheating or lack of expansion), it is the job of the radiator cap to relieve the pressure. Cooling system test kits will not only test the cooling system on a car to insure that there are no leaks, but will also test radiator caps to insure that they will open @ the appropriate pressure. Why don't $100K cars use plastic bottles? I don't know, because I don't own one (although my D certainly looks it ;) ). If I were to guess, I'd say because those kind of cars are not in the same class as DeLoreans are. Not to say that one is either better or worse. But expensive collector cars in this range are usually not driven quite as often as DeLoreans, if at all. Hence concern for originality of the vehicle is placed ahead of function. There is more that could probably be said, but anything else would simply be speculation on my part. -Robert vin 6585 "X" --- In dmcnews@xxxx, "jeremys_im" <jeremysmail@xxxx> wrote: > this raises the question if you dont install the self-bleeder AND > replace with the steel bottle AND the coolient boils what other > problems are you opening up. Since the plastic bottle would > break under these circumstances and the steel wont might this > open up more expensive reapirs elsewhere in the system? > Could this be a reason that cars in the $100,000 range still use > plastic bottles as a means of protecting more sensitive > components? > > Jeremy