Saturday I got yelled at again for not having working brake lights so I
decided to do a PO (present owner) bodge.
A while back perhaps some of you recall my post about this problem. The
snake of course has always had working brake lights, it's just that they
wouldn't come on unless a fairly large force was applied to the brake
pedal. This was apparently due to the brake switch being actuated by
hydraulic pressure. I don't know why this arrangement doesn't work
better. My old VW had the same setup and it worked fine. Perhaps it's
because the bug's switch screwed directly into the master cylinder and
the one on the snake screws into the hydraulic line T near the rear
brakes; or maybe it's because I replaced all of the flexible lines with
Aeroquip Teflon/stainless braid lines. I've lived with this problem so
long I honestly don't remember whether this has always been a problem.
Naturally the first thing I tried was replacing the switch. No change
at all. In fact the new switch leaked and I ended up putting the
original (since new) switch back in. Next I decided to try installing a
switch directly on the brake pedal itself so I bought a (Honda?)
motorcycle switch at a local bike shop. This switch has a plunger with
a spring attached so that when the brake pedal is press the plunger is
pulled to it's limit (on position) with the spring taking up the
addition travel. Unfortunately there was no way to install this switch.
Cobras have an archaic arrangement of bottom pivoting brake and clutch
pedals instead of the saner top pivoting setup found on most cars. The
pedal pivots and clutch and brake linkages are crammed inside a small
pedal box located underneath the car. This not only make things very
tight but the box is a tremendous water and dirt catcher and reservoir.
After rejecting a complicated schemes requiring cables, pulleys and
specially constructed brackets I gave up on this approach and resigned
myself to living with this "problem". But then last Saturday this guy
in a monster truckized Blazer nearly ran me over while I was slowing for
a left turn. No it wasn't this guys obscene gestures or his parting
comments that convinced me I should look into this matter further; it
was enlightened self interest. After all, the only thing between me and
the next monster truck is a rather flimsy shell of sheet aluminum and a
tacky tube frame. At the moment I don't even have bumpers on this car;
not that they would help much.
So, off I went to Fry's to see what they had that might be adaptable.
When I first posted about this problem a few months back several
responders suggested using a normally closed limit switch. Fry's had
several types but of the ones with long switch arm tabs only one looked
small enough to fit in the pedal box so that's the one I bought. No
doubt I should have made some measurements first but the switch was only
a bit over two bucks so I decided to risk it. As luck would have it I
was able to figure out a very simple way to mount it. The switch is
rectangular in shape and has two holes in the diagonal corners; just
right for securing with a couple of wraps of safety wire around the tube
that runs the length of the pedal box. The switch tab was just the
right length to rest behind the brake pedal arm. Connecting the wires
turned out to be a bigger job than mounting the switch. Originally I
had planned to run the wiring out the back of the pedal box and along
the frame to the existing brake light switch. After seeing how close
the exhaust was to the frame I decided to run the wiring inside instead.
Jeez, no wonder it gets so hot inside the cockpit. The exhaust and
muffler nearly touch the bottom side of the floor too.
Anyway it's all installed and it WORKS!! Not only that but I have
redundancy because the hydraulic and limit switches are connected in
parallel. Yes it's a bodge but it's a completely reversible bodge. No
holes, no added hardware no removed paint even. The wiring could be
improved a bit. I used those clunky plastic covered crimped connectors
because that's all I could find. The wiring runs under the carpet
(sorta) and through the roll bar hole (now removed) to the hydraulic
switch just behind the driver's seat. This is just a temporary
arrangement of course.
Roland
P.S. Thanks to all who responded with suggestions way back.
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