Brake Fluid - Do I Need Dot3

[culky]

Hello all.

My Mk1 seems to be very happy following the diy-service i've given it. So far i've replaced pads, plugs, leads, filters, oil, coolant and refrigerant in the happy knowledge that i've also saved a few quid.

But i've been a bit stumped by the brake fluid. The handbook and the filler cap both state DOT3, but the stuff seems to fall in the hens-teeth and rocking-horse poop category. I know I can't mix DOT4 and DOT5.1 because one's hygroscopic and the other isn't, so bad things happen. But what about DOT3 and DOT4? People seem to be of the opinion these shouldn't be mixed either.

Is this the case or can I flush the system a couple of times with DOT 4 and convert to that - at least it's more convenient to get hold of. If no-one knows I guess a trip to Toyota/Lexus Guildford will be called for..

Thanks for your help,

Darren

[eXOBeX]

Spot of Googling turned up this.

Basically, it would appear that DOT3, DOT4 and DOT5.1 are mixable. DOT5 can NOT be mixed with anything.

[culky]

Ah-ha.. The mystery is solved.

Many thanks! :)