2004 GMC Yukon Owner's Manual - Page 368

If you will be pulling a trailer that, when loaded, will weigh more than 5,000 lbs (2 270 kg) be sure to use a properly mounted weight-distributing hitch and sway control of the proper size. This equipment is very important for proper vehicle loading and good handling when driving. Always use a sway control if the trailer will weigh more than these limits. You can ask a hitch dealer about sway controls. 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. If your vehicle is equipped with Stabilitrak®, your trailer cannot tap into the vehicle's hydraulic brake system. Your trailer brake system can tap into the vehicle's hydraulic brake system only if: Safety Chains You should always attach safety 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. If you are towing a trailer up to 5,000 lbs (2 270 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, following 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. • 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 inches (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. 4-70