How to Tell If the Brake Booster on a Ford F150 Is Bad?

How to Tell If the Brake Booster on a Ford F150 Is Bad?

Your Ford F-150 comes equipped with a power brake system, which includes a booster, vacuum hose and fittings. This system greatly increases the pressure you can apply to the brake pedal when slowing or stopping your pickup. After years of service, though, the vacuum hose connecting the engine to the booster may harden, crack or swell, and finally leak. Also, the booster internal diaphragm may rupture or some other component may wear out and render the unit inoperative. Know the condition of the brake booster in your F-150 now by performing two simple tests at home, without the need to use any tools.

Instructions

Apply the parking brake in your F-150, but do not touch the brake pedal.

Start and idle the engine in your F-150 without touching the brake pedal.

Let the engine idle for one minute, turn off the ignition and wait for another minute before proceeding on to the next step.

Depress and release the brake pedal several times and pay attention to pedal travel as you step on it. With each application, pedal travel should begin to decrease. This is an indication that the brake booster is receiving vacuum assist from the engine. Go on to the next step. Otherwise, check for a vacuum leak on the booster vacuum hose, on the hose fittings and on the booster itself.

Depress and release the brake pedal several times, until pedal travel remains the same, to make sure the vacuum has been released from the system.

Depress the brake pedal lightly, without pushing too hard, and maintain constant pressure on the pedal. At the same time, start the engine and let it idle. As the engine starts, you should feel the brake pedal moving down slightly towards the floor. This means the power booster is working properly, according to James E. Duffy, in “Modern Automotive Technology.” Otherwise, take your F-150 to an auto shop and have it checked and the booster replaced, if necessary.

How to Replace the Break Booster on a Chevrolet Silverado

How to Replace the Break Booster on a Chevrolet Silverado

The Chevy Silverado´s braking system operates with disc brakes, which require the use of power brake boosters. Prior to disc brakes, stopping a truck required much more effort compared to the modern systems that take advantage of a vacuum created by the truck´s engine. Just like any truck part, the brake booster undergoes normal wear and tear and can lose its capacity to assist in braking. When this occurs, it is time to replace the brake booster and regain your truck´s braking ability.

Things You'll Need
Socket wrench
Flashlight
Screwdriver

Instructions

1. Lift the hood of the truck and locate the master brake cylinder -- it is located on the firewall, opposite of where the brake pedal is in the cabin of the truck. You can identify the master brake cylinder by the brake lines that are attached to it; these brake lines run from the brake linkage through the truck´s firewall and connect the brake booster to the master brake cylinder. Use a socket wrench to disconnect the master brake cylinder from the firewall, after which you will be able to disconnect the vacuum line that runs into the brake booster -- this will isolate the booster so that it can be removed later.
2. Position yourself under the truck´s dashboard so that you can access the brake pedal. Using a flashlight, look directly above the brake pedal. You will see a small metal plate on the bottom of the dashboard, where the brake linkage connects the brake pedal to the piston of the master brake cylinder. This plate is held to the bottom of the dish with screws -- remove the screws with a screwdriver and pull off the plate.
3. Remove the bolts that are located behind the brake pedal. These bolts hold the brake booster to firewall. Go back under the hood and remove the brake booster and gasket from the firewall. After this, you can install the new gasket and brake booster -- push the gasket and then the brake booster into the firewall where the old booster was located and then go back under the dashboard to secure the booster in place with the bolts that were previously removed.
4. Re-attach the vacuum line to the new brake booster and then bolt the master brake cylinder back onto the firewall. After you have done this, re-attach the metal plate under the dashboard to re-establish the connection between the brake pedal and the master brake cylinder.

Repetitive Brake Problems

Brake Issues Occur Again n Again on Jeep

Regarding Jeep Grand Cherokee, Brake Problems
Q: My vehicle is 97 Grand Cherokee with 55k miles. Wee just replaced 4th set of  brakes put on including the original set. The rotors and pads were replaced each time. That equals a new set approximately every 14k miles. It is driven in very mild conditions around town with no heavy braking. It always has the same problem. The brakes feel like they engage and disengage as you come to a stop. It gives a slow pulsing sensation.

The first evaluation always offered is warped rotors. The problem is that immediately after a brake job you still can feel this problem. It’s milder at first and then becomes more pronounced as time goes on. I also know it has nothing to do with the rear brakes because if you use the hand brake to stop you don’t get the symptom.

The second theory is some type of ABS malfunction.This has been completely dismissed by the dealer.

Any idea what the problem could be??

A: How about checking the hub that the brake rotors are mounted on? Just the day of answering your letter we a had a Mercury Crown Vic in the shop that had a brake pulsation complaint. Diagnosis indicated that the front brake rotors were the problem. From what we were told, they had been a problem for sometime. As often as possible we’ll machine the brake rotors on the vehicle. When the equipment was installed on the vehicle to machine the rotors there was a problem. The computer, yes we used computerized equipment to perform this task, was at a loss. It could not calibrate itself properly, meaning it needed help from a carbon based life form (humans). Inspection found that the hub that the brake rotor set on was off by .003" of an inch. Now .003" of an inch is just about 2 hairs stacked. That’s not much you may say. But, in the world of brakes that adds up to a lot when you carry that line out another 4 to 5". My point is that no matter how many brake rotors are installed on this vehicle the brakes will always end up pulsating,, which could very well be the problem with your vehicle. They just have to look deeper. As for the Crown Vic, there is no silicone based form (computer) that can problem solve the way the carbon forms do.