Knome_#2 said:
First off I know not to mix synthetic and non synthetic brake fluid (I use non-synthetic Valvoline Dot 4) however how can I tell what is currently in there? Is there any way to tell the two types of fluid apart?
There are two primary types of brake fluid. However, they are not synthetic and non-synthetic. What you are thinking of is silicone based brake fluid (SBBF) and non silicone based brake fluid (non-SBBF), which is based on glycol rather than silicone. DOT 3, DOT 4, and DOT 5.1 fluids are non-SBBF. DOT 5 is SBBF. You can mix any of the various types of non-SBBF with each other; however, you cannot mix any of them with SBBF. Only non-SBBF is recommended in the NSX.
To answer your specific question, according to
DOT regulations, non-SBBF is colorless to amber, and SBBF is purple.
Knome_#2 said:
all of the brake lines are steel reinforced. Was this stock?
No.
drew said:
No, it isn't, because of its inability to mix with non-SBBF (which is probably why Honda does not recommend it in the NSX). However, perhaps you are thinking of DOT 5.1 fluid?
Each DOT rating has a specific minimum boiling temperature specified, for when it is new (dry) and when it has absorbed moisture (wet). The higher the DOT rating, the higher the minimum boiling temperature, so the better the brake fluid because it is more resistant to boiling. DOT 5.1 meets the boiling point minimums of DOT 5, without the downsides of SBBF.
However, there are brake fluids that may also meet the boiling point requirements without the DOT rating. For example, Motul RBF 600 has boiling points of 593F dry and 420F wet, which exceed the DOT 5.1 minimums of 500F and 356F, but it is classified as a DOT 4 fluid. To see the boiling points of most popular brake fluids, click
here.