lw395
Well-Known Member
Because these are very wicked bits of equipment?
Obviously it should not leak air.
But it's got at least two joints in its plumbing each of which is an unnecessary point of failure for your engine. Since I regard the engine as something I want to always work, I don't think it's desirable to add failure mechanisms. Bearing in mind that the heater normally has to be removed to service it, it seems to make sense for it to be independent.
The number of threads you get on here from people with grief due to air leaks in their diesel system seems fairy persuasive to me.
However if there is good reason to do it that way, so be it, but it seems reasonable to make people aware that any air leak will stop their engine.
As David2452 points out there are other good reasons for having the supplies independent.
Having to bleed the heater line when you've changed the engine filter seems like something to avoid IMHO.