Silicon Brake Fluid

[Nourish]

I'm about to make up the brake lines for my project bike and am considering using silicon brake fluid - supposedly it won't damage paint or absorb water. Besides it's cost what are the drawbacks of using it and would it be compatible with the 70/80's Ducati Brembo master cylinder and 90's Aprilia Brembo caliper rubber seals? Cheers

[Major Softie]

No NO NO!!!!


Brembo brakes have natural rubber seals that are incompatible with silicone brake fluid. You can use 5.1, but do NOT use DOT 5. This could result in anything from leaking to complete brake failure.

This is true even for new Brembo products. There's info all over the web about it. I used to be able to find the official Brembo statement about it, but it didn't pop up this time.

[dougie]

If you have a pair of Brembos in proper condition and braided SS brakelines, then fresh Dot 4 fluid is just fine.

[vanzen]

They tried to make me go to rehab, I said,

No NO NO!!!!

[dwerbil]

[DanielMc]

Can I ask for a brief explanation of the difference (if such exists) between Dot3, Dot 4 and Dot 5.1?

[Major Softie]

Can I ask for a brief explanation of the difference (if such exists) between Dot3, Dot 4 and Dot 5.1?

Boiling point.

The higher standards have higher boiling points, both dry and after absorbing moisture, but they are all glycol based, rather than the silicone base of 5.

[moosehead]

Hey Nourish....arn't you glad you asked!

Now I call that "A REPLY"

[Jean]

I hope he got the reply in time!!
All that work...

[Nourish]

yeah I got the reply in time, I took the tank off and wrapped the fairing up and had a bucket of soapy water to hand - I'm a clumsy sod, Thanks all for the advice - Cheers