brake fluid mythbuster

I have a 97 Discovery and my parts supplier tells me that the ONLY brake fluid to use is this special brand Castrol GT/LMA Dot 4 brake fluid. The sales guy tells me that other brands don't have the protection that Castrol has and other brands would break down the seals quicker. Is this a myth or are there other brands that will work just as well. Are there other brands that works just as good as long as the brake fluid is a Dot 4? Thanks. chrisusvi

no doubt someone wiff a GCE in brake fluid will say i'm wrong. if your vehicle needs DOT4 then put DOT4 into it.
if a sales man is trying to punt brand 'A' its for a reason and not always cos its best.

he's on more commission if he sells brand 'A'

he has a **** load of brand 'A' he needs to shift

he has a bet with his boss he can shift x ammount of brand 'A' in a day

brand 'A' is nearing its sell by date

of course it goes without saying the steer clear of ' magic mickey's universal cheapo brake fluid'

as long as you use the same dot no, ie DOT4 or DOT5 in the whole system then its ok, i prefere to use ' magic mickey's universal cheapo brake fluid' as my clutch drinks it like the doris sups wine but each to their own eh