I'd planned on last weekend being my spring
get-the-snake-ready-for-the-year ritual, but only managed to complete
about half of the items on my list of chores. What inspired this
particular outburst was having yet another driver yell over to me at me
at a stop light that my brake lights weren't working.
When I got home I went through the usual rigamarole of confirming that
they were working. But this time I decided to experiment a bit figuring
that even if they did work, if no one could see them it hardly mattered.
In the past I'd speculated that maybe they were too dim to be seen,
especially in bright sunlight. I even contemplated replacing the stock
bulbs with the two-element halogen bulbs now on the market and maybe
rigging up some sort of reflectors to put behind the bulbs. The Hillman
Minx tail lights that came on the car don't have reflectors, at least
not in the configuration installed by AC Cars on Cobras. The backs are
open to the trunk area for easy bulb access, I assume.
But after viewing the lights while they were on, I decided that maybe
dimness wasn't the problem after all. They weren't the brightest tail
lights I've ever seen, but they seemed bright enough. Maybe they just
weren't coming on every time I pressed the pedal. I sat in the car with
the engine off so that the ammeter needle would be steady enough to tell
when the lights came on. No malfunction there; they came on
consistently every time I press the brake; but only when pressed firmly.
The required pressure was probably less than normally applied when
stopping, but more than what was typically required to keep the car for
rolling while stopped at a light. Another thing that occurred to me was
that not much braking is really required to slow a Cobra in normal
traffic because of the gearing. I let engine friction do about 90% of
the braking in traffic. Even in 4th gear speed can be reduced quite
rapidly by letting off the accelerator. In fact it's part of the
feeling of control one has when driving a Cobra. No doubt it's also a
danger if relied on too much.
Still I figured it wouldn't hurt to look into reducing the amount of
pedal pressure required to turn the lights on. Since the brake light
switch was the original 30 year old hydraulic pressure unit installed at
the factory, that seemed like most likely place to fix things. I was
able to buy a new switch at a local auto parts store for $4; I didn't
even need a part number. It's times like this when I'm truly grateful
that my car is half Ford.
The installation didn't seem too complicated but I decided while I was
at it I would flush the brake fluid too. Access to the switch was
straight forward only requiring jacking up one side and removing the
left rear wheel; fairly easy with center lock knock-offs. The difficult
part, as I saw it, was how to install the new switch without introducing
nearly impossible to remove air. I thought about pressurizing the
system with my Eezzibleed first but decided against that since this
might result in very rapid fluid loss, and make a huge mess to boot.
The recent clutch bleeding experience was still fresh in my mind. What
I ended up doing was filling the new switch with brake fluid and hoping
that it would stay in place by capillary action when I tilted it on its
side to install it. Next I removed the old switch, stuck the new one in
as quickly as possible screwed it in finger tight.
Now I was ready to pressurize the system. This time the Eezzibleed
worked as advertised. One of the easy to seal metal caps fit the brake
reservoirs perfectly and I was able to get things setup in less than 5
minutes. I started at the brake switch by un-screwing it enough to
allow the pressurized fluid to flow past the threads. Since it was
impossible to tell when all of the air was out I just let it go for what
seemed a reasonable length of time then re-tighten the switch with a
wrench.
Next I went to the right rear, farthest wheel from the master cylinder,
and connected up the bleeder tube and bottle. I had bought a new one
litre bottle of Castrol LMA for the occasion so I let the fluid flow
until the bottle was nearly full. It was ratifying to see that the
fluid coming out was a clean and clear looking as the fresh LMA going
in. When I had done the clutch the old fluid had been quite murky
looking.
While I had the wheels off I figured it was a good time to wash them;
wires being a bit of a pain to clean while they're on the car. I was a
little sadden to note that my beautifully rebuilt and re-painted wheels
were starting to show the wear and tear of use. The price to be paid
for having a driver rather than a show car, I suppose. Well, maybe some
day I'll go for that pricey Halibrand conversion.
Something that disturbed me even more was the amount of wear on the
relatively new BF Goodrich TA R1s. I'd opted for road racing rubber
rather than the soft autocross compound to increase longevity. The rear
tires were quite noticeably worn. I doubt there's much more than 2000
miles on them. Time to rotate. I could feel shipwright's disease
setting in.
I continued the bleeding/wheel cleaning/rotation ritual, finishing at
the rear then switching to the front master cylinder and wheels and
finally ending with a drive around the block to dry off the wet wires.
It was time to see if I had done any good. Again I pressed the brake
pedal and watched the ammeter needle. Maybe, just maybe, the pressure
required to turn on the lights was lower, but not enough to really
matter. Sigh.
Roland
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