BRAKE FLUID
The great brake fluid debates have raged since before the first internet was invented. For almost 30 years I used and was satisfied with DOT 3 in my Healey. Only after a full brake system rebuild did I change to DOT 5. My choice for Silicon was based upon my much-reduced use of my Healey and its increase in hibernation time.
Since DOT 5 is not subject to absorbing water vapor, internal water-caused corrosion brake system internals are much less subject to corrosive deterioration. After a 24 year period of no-maintenance installation, a mysterious loss of a relatively small amount of fluid with no deterioration in brakeing, and a 30% discount in brake parts from Moss, I decided to rebuild all brake components. When examining each component during tare-down, I found ALL components to be in very close to pristine condition with no observable requirement for rebuild. (The fluid loss was finally found this week coming from the brake master cylinder where the seal would expand and seal when activated and seep slightly on contraction.)
My recommendation is for Silicon DOT 5 for Summertime Healeys an DOT 3,4, or 5.1 if you have used these fluids previously and are not rebuilding all components or you have no problem doing a full flush every 2 years. Last, the price of Silicon DOT 5 is much more expensive than DOT 3,4,5.1 and I recently purchased a pint at NAPA for $17 and a quart from Amazon for $14 + $13 shipping. Considering my present age and the longevity of my past rebuild with DOT 5, I see my brake system effort as my last.
BRAKE SWITCH
After replacing my original pressure brake switch after 30 years and then 3 Moss switches within the next 6 years, I decided to install an electric brake switch in parallel. Scavenged from a salvage yard, my electrical switch was mounted on the plenum under the dash and activated by the foot peddle arm. I suggest changing to an electrical brake switch as its response and maintenance is far superior to the Healey’s original pressure switch.
Hope this helps,
Ray (64BJ8P1)