What do you do when your vehicle loses power and you are going down hill really fast?
You did not say, but I am guessing you are trying to tell us the power brakes are no longer “power.” Is that the issue?
If so you can put the car in a lower gear to help slow it and use both the foot brakes and the hand brake to help slow it. When you get it pulled off the road, then you get on the cell phone and call for a tow.
Now how about telling us the full story?
I can picture you texting this as you careen down a mountain road, certainly hope not.
If your motor dies you still have some power brakes because the brakes maintain vacuum pressure for a couple of stops before the brakes get hard to press. So don’t waste the brakes, apply good steady even pressure and stay on the petal until you bring the car to a stop.
Power steering is diffeent it stops immediately when the engine quits. Still, you can steer the car. It just takes a lot more muscle to move the steering wheel. Since you are going really fast you don’t have to move the wheel much to change course. This means while you apply those brakes you can still guide the car to the side of the road and maintain control
In the west on long down hill runs you’ll notice truck emergency brake lanes. Truck brakes are driven by a system using comnpressed air. This type of brake can fail suddenly which is why these emergency ramps exist. In a pinch noone is going to mind a car using one too, if you happen to be going really fast down a major road that has them.
Don’t panic and you’ll be OK.
You don’t need power to go downhill. In fact, most cars don’t inject fuel into the engine when you go downhill. So long as you stay in gear, you have power assist for brakes and steering because the car’s motion is turning the engine.
And truck brakes are not that delicate. If so, tour buses should not rely on them. The emergency lane is for the driver who missed a gear and have to use the brakes until they fade.
If you are dependent on power devices (power brakes and steering) and you have automatic transmission (no clutch), as the car’s speed diminishes select lower gearing to keep the engine turning, into first gear when less than 10 mph.
Brake assist is actually provided by the engine’s vacuum pulling on a diaphragm in the “booster”. If your engine dies and you have a manual, you can leave the tranny in gear and turn the ignition switch to OFF (do NOT try turn it to the LOCK position…you do not want to lock up your steering) and the car’s inertia turning the engine will provide vacuum, so you’ll have good brakes. And, the engine’s compression will also assist in slowing the vehicle.
If you have an automatic, just put the tranny in neutral and press hard on the brake pedal. The hydraulics will still work, you’ll just be missing the assist. You can use the parking brake as an assist if you’d like, recognizing that you’ll need to have it looked at once you’re safely home. The pads may be fried.
You can also steer, albiet with more effort.
The most important thing is DO NOT LOSE YOUR COOL.
One time going down a particularly steep, and difficult grade of the coquihalla highway known simply as “the hill” (If you’ve ever driven BC’s coquihalla you know what I’m saying, yeah, imagine losing brakes on THAT hill), with the curve at the bottom, my buddy’s lost power in their 1996 corolla. Engine seized up and turned off.
Yes, the power steering goes, yes, the brake vaccuum only has one or two more pumps left in it.
This is what to do…press the brake pedal as hard as you can, and hold it there for as long as you can.
I know with drums you are supposed to let them cool, but if you let the pedal go, you won’t be able to get near as far back down.
Steer the vehicle, so as to avoid other’s, and put on the emergency flashers and honk your horn continuously to let others know, your coming and they better get out of the way.
Now this next part depends on the runaway lane that is available.
If the runaway lane is relatively flat or moderately sloped, use the E brake when rolling down the hill…if it is steeply sloped, DO NOT use the E brake when going down the hill, unless a crash is imminent and unavoidable.
You will need it to function once you get to the top of said steeply uphill sloping runaway lane, so that you can prevent the vehicle from rolling back towards the road. Call a tow truck.
As foolish as this may sound, in addition to this excellent advice, as a vary last resort if all else fails to bring your speed under control. I would start or be prepared to look for something “soft” to create the necessary friction to bring yourself to a halt. Obviously I’m including full brake failure with no engine braking etc.
An oil delivery truck driver made this decision when he found he couldn’t stop in time at the bottom of our steep road entry with a school bus on loading children in his path. He took out a few saplings and rolled into a ditch through a extended snowbank, but everyone was ultimately safe. The kids were “entertained” but unhurt. That’s a driver with experience. My hats off to you for even contemplating such emergency.
The advice to not use the emergency brake aggressively is good if it operates on the rear wheels and can put you into a spin. Carefully pumping it if hand operated which I prefer, can be an alternative.