> **Quick Answer:** Pump the brake pedal fast and hard to build hydraulic pressure. If that does not work, downshift through your gears to scrub speed, then apply the parking brake slowly and steadily. Steer toward the right shoulder or an uphill runaway ramp if one is available. Do not turn the engine off. Get as far right as possible and get out of traffic before anything else.
## What Do I Do the Second My Brakes Stop Working at Highway Speed?
Pump the pedal hard and repeatedly, three to five rapid pumps. On vehicles with conventional hydraulic brakes, a partial fluid loss sometimes lets you rebuild enough pressure to get one good stop. If the pedal goes straight to the floor with no resistance, pumping will not save you, and you move immediately to the next step.
Downshift. If you drive a manual, drop gears quickly: fourth to third to second. If you drive an automatic, use the paddle shifters or the manual gate on the shifter, or move the selector down through the numbered positions. Engine braking on a modern V6 or V8 can scrub 20 to 30 mph before you need anything else. Do this while you are moving toward the right shoulder, not after.
Apply the parking brake, but do it gradually. Yanking it hard will lock the rear wheels and spin you. Squeeze or pull it slowly while keeping both hands on the wheel. This is your second brake system and it works independently of the hydraulic lines.
Keep the engine running the whole time. Turning it off kills your power steering and, on older vehicles, removes the brake booster assist, making everything harder to control.
## Is There Anything on the Road That Can Help Me Stop?
Yes, and you should be scanning for it right now. Uphill grades slow you down for free. Runaway truck ramps, marked with yellow signs on mountain highways like US-6 in Colorado's Clear Creek Canyon or I-70 approaching the Eisenhower Tunnel, are built exactly for this. Drive straight into one without hesitation. The deep gravel bed will stop a fully loaded semi. It will stop your car.
Guardrails along the right shoulder can be used as a last resort to scrub speed by making gradual side contact. This wrecks the car but keeps it from going faster. A grass median or unpaved shoulder creates friction. An uphill exit ramp is better than continuing on flat highway with no options.
What you are avoiding: other vehicles, concrete barriers at speed, and any left-side contact that could push you into oncoming traffic.
## How Do I Signal Other Drivers and Get Off the Road Without Causing a Crash?
Turn on your hazard lights immediately, before you do anything else with your hands. Hold the horn. Other drivers will move away from a car that is clearly out of control faster than they react to any other signal.
Aim for the right shoulder and keep the wheel steady. Do not make sudden lane changes. If you need to cross lanes, do it gradually and only when you have a gap. At 65 mph you are covering about 95 feet per second, so every second of clear road matters.
Once you stop, stay in the car if you are on a live highway lane. Turn off the engine now, leave the hazards running, and call 911. If you are on the shoulder with room to exit on the passenger side, get the guardrail between you and
*Photo: Pexels*
traffic and stay there. Setting up warning triangles or flares 100 to 300 feet behind the car gives following drivers reaction time. For guidance on which to use, see [Emergency Triangle vs Flares: Which Is Safer on the Highway?](/emergency-triangle-vs-flares-which-is-safer-on-highway/)
## What Caused This and Will the Car Need a Tow?
Yes, the car needs a tow. Do not drive it. Common causes of sudden total brake failure include a burst brake line, complete brake fluid loss, a failed master cylinder, or a brake caliper that has seized and caused a line to rupture. Any of these leave you with a car that cannot stop safely even at parking lot speeds.
Partial brake failure, where the pedal is soft or goes low before catching, is usually a fluid leak or air in the lines. Still dangerous, still needs a tow. The only scenario where you might drive at very low speed for a very short distance is if you can confirm the parking brake works and there is literally a repair shop visible from where you stopped.
If your brake warning light came on before this happened, that was the system telling you fluid was low or a sensor failed. A grinding noise before the failure points to worn pads that eventually destroyed the rotor and damaged the caliper. You can read more about that specific symptom at [Car Making Grinding Noise When Braking: Is It Safe to Drive?](/car-making-grinding-noise-when-braking-safe-to-drive-2/)
For getting a tow from a highway breakdown, the process is similar to any major mechanical failure at speed. See [Transmission Failed on Highway: Tow or Drive to Shop?](/transmission-failed-on-highway-tow-or-drive-to-shop/) for what to expect from that call and how to handle the situation while you wait.
*Photo: Pexels*
## Common Questions
**Q: Can I still steer if my brakes fail completely?**
A: Yes. Brake failure does not affect steering. You have full control of the wheel throughout the event, which is your main tool for reaching safety.
**Q: Will downshifting damage my transmission during a brake failure?**
A: At highway speed, rapid downshifting can cause hard engagement, but transmission damage is a repair bill. A crash is far worse. Use every gear you have to slow the car.
**Q: Should I turn off the ignition to stop the engine and slow down?**
A: No. Turning off a modern car locks the steering column and removes power steering. You will lose control. Leave the engine running until the car is stopped and on the shoulder.
**Q: What if my parking brake also does not work?**
A: Use every other option: downshifting, uphill terrain, a runaway ramp, or gradual contact with a guardrail on the right side. Keep the car moving in a controlled direction and away from other vehicles until friction slows you enough to stop.
**Q: How much will it cost to fix brake failure after the tow?**
A: A burst brake line repair runs roughly $150 to $300 in parts and labor. A failed master cylinder is $300 to $600 installed. If a caliper failure damaged the rotor and pads as well, expect $500 to $900 or more per axle. Get it diagnosed before agreeing to any repair estimate.
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*Need roadside help? Visit [Tow With The Flow](https://towwiththeflow.com/brake-failure-on-highway-what-to-do/) for real answers when your car breaks down.*
Brake Failure on Highway: What to Do Right Now
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