Posted by daveykinpa [162.158.79.26] on Sunday, August 13, 2017 at 11:13:46 :
In Reply to: Dot 5 brake fluid posted by The Dodge Boys [162.158.78.145] on Sunday, August 13, 2017 at 10:24:36 :
Hello Bill,
Quickly off the top of my head:
DOT 5 is a silicone based brake fluid first designed for the military.
It does not absorb moisture like DOT 3 or 4 but will puddle the moisture in one spot and is very hard to bleed the moisture out.
DOT 5 does not mix well with DOT 3 & 4 and can cause the rubber in the system to react (swelling) to the different brake fluids. Or can cause a gunk build up in the system.
DOT 5 aerates much easier and can be a pain to bleed. Sometimes letting the fluid sit overnight before bleeding helps let the aeration settle.
DOT 5 can cause a softer pedal.
When changing from DOT 3 or 4 to DOT 5 or from DOT 5 to DOT 3 or 4 the entire system must be totally and completely flushed or disassembled and cleaned.
HTH
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