Chevrolet Silverado Classic 2007 Owner's Manual page 450

Safety Chains
You should always attach chains between your
vehicle and your trailer. Cross the safety
chains under the tongue of the trailer to help
prevent the tongue from contacting 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. If
you are towing a trailer up to 5,000 lbs (2 271 kg)
with a factory-installed step bumper, you may
attach the safety chains to the attaching points on
the bumper. If you are towing a trailer up to
your vehicle's trailer rating limit you may attach
the safety chains to the attaching point on the hitch
platform. If you are towing with an aftermarket
hitch follow the trailer or hitch manufacturer's
recommendation for attaching safety chains.
Always leave just enough slack so you can turn
with your rig. Never allow safety chains to drag on
the ground.
450
Trailer Brakes
If your trailer weighs more than 2,000 lbs (900 kg)
loaded, then it needs its own brakes – and they
must be adequate. Be sure to read and follow the
instructions for the trailer brakes so you'll be
able to install, adjust and maintain them properly.
Your trailer brake system can tap into the
vehicle's hydraulic brake system only if:
•
The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
•
The trailer's brake system will use less than
0.02 cubic inch (0.3 cc) of fluid from your
vehicle's master cylinder. Otherwise,
both braking systems won't work well. You
could even lose your brakes.
If everything checks out this far, make the brake
tap at the port on the master cylinder that
sends the fluid to the rear brakes. But don't use
copper tubing for this. If you do, it will bend
and finally break off. Use steel brake tubing.