[FWDLK] DOT 5

["Larry C. Stanley" <peerless@xxxxxxxxxxx>]

All,

The military also uses DOT 5. The main difference in a military and a
civilian brake setup is the military is a totaly sealed system and the
fluids are changed out on a more frequent basis than is done on civialian
cars. When was the last time you had the brake fluid changed on your daily
drivers? Brake fluid is not a permanent fluid.

The silicone fluid will not absorb the moisture that can get in the system.
Any moisture will lay on the lowest part of the system and start to rust.
DOT 3 and 4 will absorb any moisture at the expense of boiling point, but
if the fluid is changed occasionally that will never be a problem.

Regular bleeding (on a system that has not been serviced in a long time)
will not get the all of the contaminated fluid out (especially not the DOT
5) because the bleeders are at the top of the cylinders and are for letting
out air. Water would be at the bottom. About the only way to fully change
the fluid is to tear down the wheel cylinders and dry them out. This is a
lot of work and is why it is seldom done. But it is a very good time to
inspect all parts of the system.

I have the brake fluid changed every time I have shoes or pads put on my
daily drivers. All of my '58s get DOT 5 when the brakes are reworked. DOT 5
will not attack paint like the DOT 3 and 4 will. As little exposure to the
weather as most of our cars get, the DOT 5 should not cause a moisture/rust
problem.

Larry