[TR] Fwd: Caliper Piston Removal

Randall tr3driver at ca.rr.com
Thu Nov 12 10:54:34 MST 2009


Little early in the season for fluif wars, isn't it?
<G>

> I thought the non-issue about DOT 5 was about it having a 
> slightly lower boiling point than DOT 3 or 4, rather than a 
> reduced hydraulic capability.

Actually, the DOT 5 specification calls for a higher minimum boiling point
than either DOT 3 or 4.
Dry 3/4/5 = 205C/230C/260C
'Wet' 3/4/5 = 140C/155C/180C

But in use, the DOT 5 stays relatively dry; while DOT 3/4 will absorb
moisture and salt right through the brake lines, to give a boiling point
even lower than the 'wet' specification.
http://s258.photobucket.com/albums/hh260/TR3driver/Brake%20Fluid/?action=vie
w&current=Browing2Table3.jpg

However DOT 5 is slightly more compressible, which does result in a slightly
softer pedal.  Worse, from a racer's point of view, it becomes more
compressible as it gets hot, so the pedal gets progressively softer during a
race.

-- Randall  


More information about the Triumphs mailing list