Mk1 Brake Fluid.. - PistonHeads - PistonHeads | Cars for Sale | Car News | Motoring Forum
yep once a system has had normal brake fluid in (DOT3, DOT4 and DOT5.1), the rubber seals will fail if subjected to silicon-based fluid (DOT5). added to which there are no benefits whatsoever from using DOT 5 apart from the fact that it can last 5 years i...