Brake Fade Descending Haleakala Crater Road
Descending Haleakala Crater Road in a loaded seven-passenger minivan, you are on an 8% grade with about four miles still to go. The posted warning says LOW GEAR. You have been using the brake pedal to hold a steady 25 mph. Near a turnout, you notice a hot, sharp smell and the pedal feels low and soft; the van speeds up even though you are pressing harder. The turnout is about 200 yards ahead. Your passengers are talking and one asks why the van smells. The road curves left beyond the turnout, and there is no runaway truck ramp. You are in the right lane, with a steep drop-off beyond a low guardrail on the right. Traffic behind you is light.
1. What is happening to the brakes, and what should you do in the next 200 yards?
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The smell and soft, low pedal point to brake fade from overheating: the brake fluid may be boiling or the pads are too hot to grip. Do not continue riding the brakes. Slow early, shift to a lower gear, and pull into the turnout using gentle braking. Stop well inside the turnout, set the parking brake, and let the brakes cool. Do not pour water on hot brakes; warping or cracking can result. Warn passengers to stay clear of traffic and keep the hood closed unless there is a fire. Check the pedal after cooling; if it is still soft or the fluid is low, do not continue down the grade.
2. How should you descend the remaining grade once you leave the turnout?
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Use the engine and transmission to control speed: select a low gear before the steep section, not after speed builds. Brake in short, firm applications rather than constant light pressure, and let off to let the brakes cool between applications. Keep speed low, use turnouts to let faster traffic pass, and avoid coasting in neutral. If the pedal begins to fade again, stop at the next safe turnout. The goal is to avoid heating the brakes beyond their capacity; gravity will keep adding speed, so the transmission must do most of the work.
3. If the brakes fail completely, what is your sequence of actions?
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Stay calm, keep steering, and downshift to the lowest safe gear to use engine braking. Pump the brake pedal once or twice in case pressure returns. Apply the parking brake gradually, not in one yank, to avoid skidding; hold the release if it locks the rear wheels. Sound the horn and flash lights to warn others. Look for a turnout, a wide shoulder, or an uphill escape; if none exists, use the guardrail as a last resort at a shallow angle rather than going over the edge. Do not turn off the engine, because that can lock the steering and reduce brake assist.