By the way - how many of you that have had hydraulic brake switch failure
(the one mounted down by the right front tire, not the TR4 version up on the
master cylinder) were using DOT5 fluid?
I have had DOT5 silicone fluid in the car since about 1990, and that darn
switch is the only thing that has failed - several times. I have taken one
of the switches apart and find that all it is, is a a rubber diaphragm with
a brass button which the hydraulic pressure causes to short out the two
contacts on the inside of the molded plastic piece. What happens is that
the silicone fluid leaks just a little around the diaphragm and then
insulates the contacts so that it has trouble making contact, or maybe the
leak of the fluid keeps the diaphragm from moving far enough to make
contact. I noticed that I had brake lights only if I pushed REAL hard on
the brakes. I am thinking that other fluids are not an insulator, so that
even if a little leaks it makes no difference to the brake contacts, just a
slow leak around the switch, or they react differently to the diaphragm and
just don't leak!
Does DOT5 correlate with the failure?
Frank
(TS55223L)
=== This list supported in part by The Vintage Triumph Register
=== http://www.vtr.org
|