Which brake fluid

[jamesmatheson]

Hello everyone, I have s1 2+2 , which brake fluid is best recommended to use please?

James

[phil.dobson@mac.com]

If you are not using silicone then I just use a standard DOT 4 mineral fluid.

[chrisfell]

Subject comes up quite regularly. I use 5.1. It is not expensive and has a higher heat threshold than 3 or 4.

A point to note. The new MOT rules include a visual check on the condition of brake fluid. Dirty fluid is a fail.

[Fasthound1963OTS]

The guys at R&R Auto (Sterling, VA, USA) who’ve been keeping British cars on the road since the mid-1970’s swear by Castrol, so that’s what I am using.

[jamesmatheson]

Thanks for the reply’s, any idea on the quantity needed for a full system change?

[cactusman]

If you are just rinsing through a filled and air free system and not trying to force air bubbles out then a litre should be plenty. If you are filling an empty system and need to force air bubbles out you will probably wind up using more than a litre...

[Jeremy]

I filled my brake and clutch systems from empty, that's new everything and completely empty, and bled them, with 1 litre. There was a bit left over, not much. If you're flushing out old/contaminated stuff I think you would need more.