Unlike the sillycone stuff, DOT 3 and 4 fluids are compatible. Of course
brake can never be too clean or too new. Drain until empty, then fill
with new and there will be no problem.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Jeff Kennedy
Sent: Saturday, March 06, 2004 12:51 PM
To: vanagon@GERRY.VANAGON.COM
Subject: DOT 3 & DOT 4 brake fluid?

Hello,
 We all know that DOT 4 is the stuff to use, but the system in my van is
full of DOT 3. I'm replacing the slave cylinder now, figured it's a good
time to flush it, too, and put in the DOT 4. (Plus it should be up to 50
deg next week!). Any suggestions on how thorough I need to flush it? Was
thinking I'll just drain the reservoir, and pump it until its clear...

Cheers,
 Jeff