Are all DOT4 brake fluids interchangeable?

[televascular]

I'm going to flush my brake fluid (2003 VW Passat) this weekend. I got the OEM VW/Audi DOT4 fluid from a dealership; then I realized I needed more and went to a different dealership. They gave me BG "Dry Flush" DOT4.

I asked the guy at the parts counter if I could mix this brand of DOT4 with another, and he said yes. But he didn't look confident saying it. I just want someone to confirm this, please.

Thanks for your help!

 

[Scimmia]

yes, any DOT4 fluid should be able to mix with any other without any problem. As long as you don't use DOT5 (DOT5.1 is fine), just about ANY brake fluid wouldn't be a problem.