Why did front brakes on 1994 Ford Taurus not function when rear brakes failed?
I have a braking system question for you. The vehicle I drive is a 1994 Ford Taurus 4 door sedan w/ automatic transmission with a 3.0 L engine and standard hydraulic brakes (not ABS).
I was recently on a drive and was comming to a stop light. When I applied the brakes there was some firmness, then the entire pedal sank to the floor. I pumped the brakes but no response. I ended up ditching the car into someones yard and took out some shrubs, to avoid entering a busy intersection. After the car was towed and inspected, it appears that my rear brake lines had become rusty and had a hydraulic rupture.
I have always be under the impression that the front and rear braking systems were independent, so that if one failed you still have some braking function from the other.
Are the Ford Taurus front and back hydraulics independent? If so, why did I totally lose all braking functionality when my rear brake line ruptured?
Tagged with: 1994 ford taurus • automatic transmission • braking system • braking systems • firmness • ford • ford taurus • functionality • hydraulic brakes • hydraulics • intersection • rear brake line • shrubs
Filed under: Ford Taurus 1992-1995
With an ABS system, this would not have happened, as the wheels are all separated hydraulically. with a non-ABS system, the proportioning valve actually has all the lines hooked to it in order to balance front/rear braking. With any major fluid loss, as in a burst hose or line, the proportioning valve is still trying to achieve 60/40 pressure, and as such will allow pressure to go to the rear, which then squirts out of the hose/line, and kills the pressure to the front. However, the emergency brake is always mechanical, for that very circumstance. Seems odd we call it a parking brake nowadays, because folks seem to forget its true purpose. For an EMERGENCY!!!!
There are a couple of possible issues here. Maybe your front brakes weren't working properly and your rear brakes had been providing all your stopping power? The front/rear brake systems are not totally independent. They share a vacuum booster and master cylinder. There is also a proportioning valve which directs roughly 60% of your braking power to the front brakes and 40% to your rear brakes. A failure in any one of these components can cause the problem you mentioned.
You also have the emergency or parking brake, which applies only the rear brakes, but is a mechanical system totally separate from the hydraulic system. You should have used that to help you stop.
You where probably driving with only your front brakes for a while. You probably ran low on brake fluid when your lines burst on the rear brakes. The rest of the fluid went in to the calipers as your your brakes wore out. Once there was more fluid in the calipers than in the master cylinder, the master cylinder sucked air and you lost your front brakes as well
Jim is right.
You were driving with just half the brakes working, and when you went low of fluid there were no brakes left.
Scott is telling the way it is , You need to be aware of your brakes that is one thing that will wear out over a short time , The front brakes will start working first then a second after that the rear will come into play , Once the line broke you Had no brakes except the emergency , hope this helps , listen to Scott.
Your front brakes didn't work because all the fluid leaked out. No brake fluid means no normal brakes. You should still have some braking ability because the parking brake is totally seperate.
Introduction
Thanks to a number of mechanical checks and balances, brake failure rarely occurs. But even though most drivers will never have to experience it, it doesn't hurt to be prepared.
Instructions
Difficulty: Challenging
Steps
1. Size up the traffic situation and base your decisions on the whereabouts of other vehicles, intersections or steep hills.
2. Look for a safe place to steer your car and quickly downshift to low gear (this applies to both manual and automatic transmissions).
3. Build up your brake pressure by pumping the brake pedal fast and firmly. It should take three or four pumps to get the brakes to work. Don't pump anti-lock brakes — press down hard on them instead and plan on taking longer to stop. It is normal to feel pulsation at the brake pedal if you have anti-lock brakes.
4. Use your parking brake if the pumping solution is ineffective or not recommended. Release it quickly if the car starts to skid.
5. Don't forget to steer. Swerve only if it's absolutely necessary — doing so can cause you to lose control of the car.
6. Throw your car into reverse if all else fails. Note that this can cause serious damage to your transmission. (This does not actually work. Your automatic transmission will lock into neutral and shut the car off which causes you to lose power steering too. Manual transmissions will not go into gear either they will just grind.)
Tips & Warnings
- Sounding your horn and flashing your headlights will warn other motorists.
- Turn on your emergency flashers once you've come to a complete stop.
- Try to remain calm - panicking can cause you to make mistakes.
- Use a cell phone to call for roadside assistance if your brakes continue to fail. Wait in your car or another safe place until help arrives.
- Get your brakes and brake hoses checked every 6 months.
- A not uncommon cause of inability to brake is a soda bottle or ball rolling under the pedal: clean out under your seat!
- If you have anti-lock brakes, do not pump them. Autos sold in the United States must contain fail-safe brake systems. If you have problems with your anti-lock brakes, simply press down hard and plan on waiting longer to stop.
- Do not drive for any long period of time with the brake light on. Add brake fluid and go see your mechanic.
Most of the replies you have recieved are either from crackpots or half wits (several know what they are talking about but oversimplified). First off DO NOT DRIVE the carAT ALL untill this is repaired. Adding fluid is not going to work in most cases AND putting the car on the road in this condition CAN RESULT IN CRIMINAL CHARGES called reckless endangerment. The vehicle must be repaired before being driven! Now on to the problem.
Without more information an exact answer can not be given. But the description you have given makes me suspect that one of the brake lines going from the master cylinder to the rear brakes ruptured. This isnt uncommon on an older car as the lines are steel and rust happens. When one of these lines breaks you will lose all pressure to the opening in that line, and no pressure will be applied anywhere else. This is the law of the path of least resistance. There is a valve assembly above the real axel that proportions the pressure to the rear brakes. If the rupture happens between this valve and one of the rear brakes you will still have some braking, but if it happens infront of this valve you will lose all brake power. There was a time that Detroit put the money into the brake system but we all know what happens when something works too well, the manufacturer starts cutting quality until the product is “just good enough”… Too bad the car prices don’t reflect these cutbacks.