Geo 1995 Prizm Owner's Manual page 158

It's important to have the correct hitch equipment.
Crosswinds, large trucks going by, and rough roads are a
few reasons why you'll need the right hitch. Here are
some rules to follow:
Will you have to make any holes in the body of your
vehicle when you install a trailer hitch? If you do,
then be sure to seal the holes later when you remove
the hitch. If you don't seal them, deadly carbon
monoxide (CO) from your exhaust can get into your
vehicle (see "Carbon Monoxide" in the Index). Dirt
and water can, too.
The bumpers on your vehicle are not intended for
hitches. Do not attach rental hitches or other
bumper-type hitches to them. Use only a
frame-mounted hitch that does not attach to the
bumper.
Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the tongue
of the trailer so that the tongue will not drop to the road
if it becomes separated from the hitch. Instructions
about safety chains may be provided by the hitch
manufacturer or by the trailer manufacturer. Follow the
manufacturer's recommendation for attaching safety
chains and do not attach them to the bumper. Always
leave just enough slack so you can turn with your rig.
And, never allow safety chains to drag on the ground.
Trailer Brakes
Does your trailer have its own brakes? Be sure to read
and follow the instruction for the trailer brakes so you'll
be able to install, adjust and maintain them properly. If
your vehicle has anti-lock brakes, don't try to tap into
your vehicle's brake system. If you do, both brake
systems won't work well or at all.
Even if your vehicle doesn't have anti-lock brakes,
don't tap into your vehicle's brake system if the trailer's
brake system will use more than 0.02 cubic inch (0.3 cc)
of fluid from your vehicle's master cylinder. If it does,
both braking systems won't work well. You could even
lose your brakes.
Will the trailer brake parts take 3,000 psi
(20 650 kPa) of pressure? If not, the trailer brake
system must not be used with your vehicle.
If everything checks out this far, then make the brake
fluid tap at the upper rear master cylinder port. But
don't use copper tubing for this. If you do, it will
bend and finally break off. Use steel brake tubing.
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