Synthetic DOT 4 brake fluid

[George Selby]

At 09:31 PM 7/18/2006, you wrote:
>Just saw some Prestone IIRC syn DOT 4 at my local
>FLAPS...good or crap?  Just curious.

IMHO, not good at all.  Once it started getting hot a couple of months ago 
here in Eastern NC, I was having trouble with my brakes locking up in my VW 
Jetta.  Got so bad I couldn't drive the car.  I had replaced everything 
brake related in the car within the past couple of years, sometimes twice 
to repair this problem (which only occurs when it is hot.)  I had been 
using the Valvoline Synthetic DOT 4 fluid, as it was the only type of DOT 4 
fluid my local FLAPS stocked.  I finally decided to flush the system and 
try regular DOT 4 fluid (obtained at a NAPA) and as soon as I did so, the 
problem disappeared.  So IMHO the synthetic has a problem with heat 
expansion, even though it has a temp rating some 100 degrees higher than 
non-synthetic DOT 4 brake fluid.


George Selby