<VV> Corvair Master cylinder

Chris & Bill Strickland lechevrier at earthlink.net
Fri May 16 15:00:33 EDT 2008


Concerning DOT 5 (silicone) brake fluid:

My big complaint with the non-silicone fluids is that, in spite of 
manufacturers claims to the contrary, they are not a lubricant (since 
when is alcohol a lubricant?).  Especially after they have drawn in some 
moisture.  Those little packets in some overhauls kits -- silicone based 
brake assembly fluid (included because brake fluid is NOT a lubricant), 
ala Raybestos #BAF-12 Hydraulic Brake Cylinder Assembly Fluid (Carquest 
#TBAF 12) -- 
http://www.autoparts2020.com/rsdev/part_detail.jsp?PART_HDR_ID=40378&cat=2,3,4,5,9
Also works well on assembling the fuel filler tube to gas tank hoses.

Now, I am not going to reccomend that you use silicone for racing 
applications -- DOT 5.1 type fluids are superior -- but I have used 
sisicone DOT 5 for a number of years, including in my bug-eye Sprite, 
which sits for years at a time. Previously, with conventional fluids, 
everytime I would want to move / use it, it meant overhauling the clutch 
and brake systems, even though I'd be using "proper" British fluid, and 
sometimes they wouldn't work even while you were actively driving them - 
damned English "rubber".  With the silicone fluid, they work everytime, 
even after long periods of storage.

I also use silicone in my daily driver Fieros, because the aluminum 
stepped master cylinder design is subject to physical wear without the 
improved lubrication of of the silicone fluid. Both in flushed systems 
and in unflushed systems.  Mixing of the two types produces some ugly 
mixtures, but the evidence, to me at least (I haven't had a braking 
failure), is that they work in daily driven scenarios in spite of 
appearences and foreboding naysayers.

I have not experienced the supposed "compressability issues" some have 
mentioned -- maybe they just don't know how to bleed brakes and blame 
the fluid -- I don't know -- but I do not find it an issue in mine or in 
any other car (hot rods with fancy expen$ive paint jobs) I've worked 
on.  Did I mention it won't eat up your paint?  And, although it does 
not absorb moisture like conventional brake fluid, neither does it suck 
it out of the atmosphere to the point of fluid failure due to 
contamination.  Yes, either type of fluid should be changed every couple 
years, and, if you get right down to it the whole system should be 
overhauled at the same interval -- whatever gives you peace of mind ...

And, back to the main topic, yes, I endorse a dual system master 
cylinder -- between us, both my wife and I have had a brake hose failure 
(one once an FC - wife) and they tend to provide more excitement in 
one's life than the most thrilling carnival ride.

Godspeed & goodstopping,

Bill Strickland


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