If the vehicle pulls to one side during braking, check the front wheels. Do not assume the pulling is a brake related condition. Check the wheel alignment first.
Test the brakes on a dry, clean, reasonably smooth, and level roadway. Do not test the brake performance when the roadway is wet, greasy, or covered with loose dirt. These conditions prevent the tires from gripping the road equally. A crowned roadway also affects brake testing. This condition shifts the weight of the vehicle toward the wheels on one side. The results are also affected when the roadway is rough enough to cause the wheels to bounce.
Test the brakes at different vehicle speeds with light and heavy pressure. Do not lock the wheels or slide the tires on the roadway. Heavily braked wheels will stop the vehicle in less distance than locked wheels. There is more friction present with a heavily braked tire than with a sliding tire.
External Conditions That Affect Brake Performance
| • | Uneven breaking is caused when tires have uneven contact and grip on the road. Check that the tires are equally inflated and that the tread pattern on the right and the left tires are approximately equal. |
| • | Load the vehicle evenly. An uneven loading creates uneven braking. The most heavily loaded tires require the most braking force. |
| • | Loose front wheel bearings allow the brake drum and the wheel to tilt. This causes inconsistent contact with the brake linings and erratic braking action. |
| • | Misalignment of the front wheels, the camber, and the caster settings cause the brakes to pull the vehicle to one side. |
System Tests
- Inspect the air lines and tubing for kinks, twists, or dents.
- Inspect the hoses for wear, drying, or overheating. The hoses should not rub against or touch anything with sharp edges.
- Inspect the tubing clamps and the clips. The tubing should be firmly held in place and not sag or vibrate.
- Inspect the nylon lines. Keep the nylon lines away from extreme heat sources.
- Inspect the reservoir support bolts, the straps and the strap nuts. Tighten the components if necessary.
- Inspect the air line connections. Tighten the connections if necessary.
