|
Back to Home Page
12 volt pump conversion
If you have ever wondered what you would do if you got a flat
or if you are just tired of carrying around all of those CO2 cartridges
in addition to your flat tire repair kit, here’s an easy
solution. (Many thanks to Dave Searle and Motorcycle Consumer News
for this great idea).
Start off with a 12 volt Campbell Hausfeld pump. I bought mine
at Wal Mart for $18.99 (photo
#1). This is the kind of pump used
for emergency auto tire inflation, and it just plugs into a cigarette
lighter. Since such a large device would be impractical for use
with a motorcycle, you need to make it as small as possible so
it will fit under the seat of your bike. Do this by first removing
the screws that hold the two halves of the plastic case together
(photo
#2). Then snip the cigarette lighter adapter off (photo
#3) and remove the wires that go to the switch by heating the
solder and pulling them loose (photo
#4). All of the other stuff (the
switch, the light, and the pressure gauge) will be discarded in
the interest of making it small.
Pull firmly on the plastic fan to separate it from the pump shaft.
At this point the pump will be separated from everything but the
pressure gauge and
the air hose. Cut the wire that goes to the cigarette lighter adapter to about
36 inches in length, slide two pieces of shrinkable tubing over the ends, and
solder it to the two terminals that originally went to the switch (photo
#5). This should be plenty long enough for use with a bike but short enough
to save some valuable space when folded up. Then heat the tubing with a lighter
to make it shrink (photo
#6). Next, fold the wires over and secure them to
the side of the pump with a zip tie (photo
#7). You can see now that the tubing
will keep the terminals from shorting against the side of the pump. The next
step is to attach a red and a black alligator clip to the other end of the
wires (photo
#8). Notice that one of the terminals has a little red dot beside
of it. This is the hot terminal and is the side you attach the red alligator
clip to. The other terminal is the ground; attach the black alligator clip
to that side. To make the pump run, simply hook the red clip to the positive
side of your battery and the black clip to the negative side and voilà!
The pump works! Another option is to use the matching plug for your electric
vest or Battery Tender in place of the alligator clips (photo
#9). This is
what I chose to do, as it will make hooking the pump to the battery easy and
fast. If the pump model you bought doesn’t have the terminals marked,
just touch the bare ends of the wire to the battery terminals on your bike
(make sure you are holding the plastic-covered part of the wire when you do
this!) and if it works, note which wire touched which terminal. If it doesn’t
work, switch sides. Then install the alligator clips or plug end accordingly.
The next step is to remove the pressure gauge. I just pulled on
the tubing that connects the gauge to the pump and it came right
off the little brass
nipple. Then pull on the nipple with a pair of vise grips (photo
#10) removing
it from the pump body. It is important to seal this opening up because the
pump will leak air if it isn’t sealed up. This was easily done by filling
the little opening with solder.
The last step is to modify the fan blades so the fan can be reinstalled
closer to the pump body. Do this by cutting the blades a little
shorter with a utility
knife (photos
#11 & 12), and pushing it back down onto the shaft as far
as it will go without contacting the terminals. Finally, cut the shaft off
with a Dremel to make it shorter (photo
#13). This is all there is to it, and
the final product is small enough to fit into a plastic sandwich bag (photo
#14). Actual measurements are about 7 inches by 4 inches by 2 inches, which
easily fits under the seat and only takes up about as much space as all of
those CO2 cartridges I used to carry around. When making an emergency repair,
this is peace of mind since CO2’s will just barely fill a rear tire enough
to ride to the nearest air pump, unless you happen to carry about ten of them.
The big benefit is that now, after plugging a tire puncture, I can completely
refill the tire to the proper pressure in about five minutes.
From now on I’ll ride with the added security of knowing
that I can repair almost any flat and be on my way (searching for
a new tire no doubt) in just
a few minutes. This project was easy and fun, and it only took about an hour
to complete.
If you would like to have one of these pumps but don’t have
the time to make one yourself or don’t feel comfortable attempting
this project,
email me and I’ll
be glad to make one for you.
Back to Home Page
|
