Why does our Manual say NOT to use Synthetic Brake Fluid? I'm going to be flushing out all the brake fluid on my Z over the weekend and while reading the manual I see that it stated not to use Synthetic. Most Brake Fluids are Synthetic and I was thinking of running the Valvoline. Is it possible they mean not to top off the brake fluid with Synthetic or just not to use it period. Any help would be greatly appreciated.

BTW I searched but the question was never answered.

 

Valvoline works fine< but i now use prestone cause if a higher boiling point

 

Use exactly what the Owners Manual tells you to use:

Sure, they are all "synthetic", after all, you don't see a brake fluid well and it doesn't grow on trees, right? The warning about synthetics is in regard to DOT 5 brake fluid. DOT 5 contains silicone and that will damage the rubber in the brake system of most cars.

 

Thanks for that information. I just didn't know the reason behind it and I was looking all over the place.

 

BTW - I've been using Valvoline for years now - you'll be fine with it.

 

DOT 4 is ok though, correct?

 

Correct , hell i don't even use Dot 3 in my 88 ford.

 

Thank you sir... I'm sure this will answer for those looking in the future.

 

Thanks terrasmak.

I figured being that I've been running RBF600 for 2 years without issue that was the case.

 

DOT 3, 4 and even 5.1 are perfectly fine to use as they are all glycol based. dot 5 is the only DOT rated fluid made of silicone thats commonly available.