Dot 4

[DeanR]

Just double checking that it's ok to use DOT 4 brake fluid in our bikes. My NAPA store has big bottles of DOT 4 for $1. (AC DELCO which is interesting). I'm gonna have to use a lot to track down a problem, so why not use the cheap find.

[bikerphil]

Yes, you can use DOT4 in place of DOT3, it just has a higher boiling temperature than the 3 which is a good thing. Both will mix together with no problem.

[cajun31]

Just double checking that it's ok to use DOT 4 brake fluid in our bikes. My NAPA store has big bottles of DOT 4 for $1. (AC DELCO which is interesting). I'm gonna have to use a lot to track down a problem, so why not use the cheap find.

I found this on the Autozone site.
DOT 4 absorbs moisture faster than DOT 3 brake fluids and should be changed more regularly. DOT 4 fluid typically has 50 to 65% glycol ether base with 20-30 % Borate Ester which helps resist the boiling of the fluid, meaning you have 3.7% moisture in your DOT 3 fluid the fluid will boil at roughly 290°F.