[Spridgets] Master cylinder maintenance

[Allen Hefner]

And one other thought, Phil. Glycol based brake fluid is hygroscopic, so it
attracts water. Make sure you flush the brake (and clutch) system every two
years to replace the old fluid. Racers do that after every race.

In my old Mitsubishi I didn't do this and lost brakes in the PA foothills.
Loads of fun trying to slow down into the Hegins valley. When I got home, I
flushed the system and the fluid was blood red with rust.

Changing the fluid is not as important with silicone, but I still like
glycol better. It gives a better pedal feel, and IF there is any water in
the system from humidity in the air, it won't pool at low points in the
brake pipes as it will with silicone fluid. Silicone brake fluid is
hygrophobic.

BTW, Castrol GT LMA brake fluid is DOT 4, so it has a higher boiling point
than the cheaper DOT 3. Stick with the good stuff.

(How'm I doin', Ed?)

 Allen Hefner
Norristown, PA

*Current:*
2006 Chebbie
*Former:*
1963 Sunbeam Alpine Series III
1967 Triumph TR4A IRS
1964 VW Type I
1967 VW Type II
1967 Rover 2000TC
1977 MG Midget

On Tue, Jul 10, 2012 at 4:47 PM, Phil Nase <nases at verizon.net> wrote:

> Thanks Allen.  I thought that might be the news I would get.  I just put a
> 5 speed in and bled the clutch manually and with an EZ bleed over 5 times
> and still had only a "so-so" pedal.  Yesterday the seeping started.  I
> can't seem to keep anything I fix on this car to stay fixed.  Funny thing
> is that the brake pedal is good, hopefully for a little while longer.
>
> I thought I might have to flush it with alcohol but didn't know which
> kind.  But if I can flush it with DOT4 that's good I still have a bunch on
> the shelf unopened.  Wheel cylinder rubbers are pretty cheap I think.
>
>
>     Phil Nase
> Quakertown, PA
> http://home.comcast.net/~philnasecpa/
>
>
>
>  On Jul 10, 2012, at 4:10 PM, Allen Hefner wrote:
>
>  Phil,
>
> As many listers know, I have never been one for sillycon brake fluid. By
> making the switch FROM silicone back to the glycol, my bet is that you will
> eventually wind up rebuilding all of the brake system. Maybe not all at
> once, but these things don't like change.
>
> The problem is in how the rubber bits absorb the fluid. They are now used
> to breathing silicone.
>
> I suggest you rebuild the MC and stay with what you have been using.
>
> If you really want to change, you should flush the system with new, DOT4
> brake fluid. After you are certain that everything has been flushed thru,
> bleed as normal. And have the rebuild kits on hand for your calipers and
> wheel cylinders.
>
> And don't follow too closely for a while, in case you have to stop quick.
> Safety Fast!
>
> Allen Hefner
> Norristown, PA