Pedal to the floor, but now the ABS and traction lights are remaining on

Hi and thanks for using 2CarPros. Com.

If the brake pedal is now good, the lights are on, and you replaced the sensor and module, have you confirmed that the wheel speed sensor ring isn't loose or damaged? It is not something normally checked and I have no idea how bad the bump was or what caused the pedal to go to the floor. If you find the ring is damaged or moved, here are directions for replacing one.

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Wheel Speed Sensor Ring - Front

Removal

1. Remove the front halfshaft.

2. Using a suitable driver, remove the ABS wheel speed sensor ring.

Installation

1. Install the new ABS wheel speed sensor ring and the tools on the halfshaft as shown in the previous illustration.

2. Install the ABS wheel speed sensor ring to the dimension as shown.

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Now, if nothing appears to be at fault, you need to check for trouble codes. That way I can provide a pinpoint test to determine the issue.

The last picture I attached is a symptoms chart. I do not know if it will help, but it may.

I hope this helps. If it does not, please see if trouble codes related to traction control or ABS are present and let me know what they are.

Take care,
Joe

When installing a new ABS module/Hydraulic Control Unit (HCU) assembly, it must be configured (either by download/upload or uploading the as-built data method). Do not swap ABS modules between vehicles, the ABS module and the Hydraulic Control Unit (HCU) are calibrated as an assembly.

With that in mind, you need the IDS (integrated diagnostic software) and the VCM (vehicle communication module) to configure the unit and to get rid of the B2900. When that is deleted, the wheel sensor code should be able to be deleted.

You mentioned that you want to reinstall the old module. If you have it and it is good, that may make life easier. Also, If the ABS module had a leak internally, you would be losing fluid. And, the speed sensor code needs to be cleared, but I do not think that will work until the module is configured.

I have all the directions for the module replacement if needed. Let me know.

The ABS master pump is not functioning correctly. Some system requires it to be bled with the aid of a scan tool. You can try this. Drive slowly on a sandy or slippery patch of road and pump on the pedal hard, try to get the brakes to lock and activate the ABS.
If it does not work and initial problem was due to the same fault code, the ABS master pump is most probably faulty and needs to be replaced.

You are welcome.

Glad to know you have resolved the problem.

This problem does not occur solely in Fords, all other makes do have this problem as well.

Brake fluids are hygroscopic and the moisture absorbed into the brake hydraulic system would result in sedimentation leading to rust and corrosion of valves. Over time, this valves would lose their ability to seal tightly resulting in internal pressure losses. The system is unable to maintain a residual pressure and the brake pedal would have to travel far to get sufficient hydraulic pressure, which is usually insufficient to brake efficiently unless you pump the pedal fast.

Any vehicle over 2 years are prone to this and one way of minimizing this problem is to replace the brake fluids at least once a year. Brake fluid quality and performance starts deteriorating after 9 months and 12 moths is a reasonable period to replace them. Replacing brake fluids would also slow down deterioration of seals in the braking hydraulic system, prolonging service life.

More then likely in the ABS event caused something to leak and you now have air in the system which can compress.

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

So we need to start with checking the system for leaks so that we are not losing fluid.

Let me know what you find with this information and we can go from there.

Okay. That is good but you may still have an internal leak so you are not losing fluid. The master cylinder could be the issue so I would suggest with bleeding the base brake system and see if you get air out. If there is no air then I suspect the master cylinder is the issue.

https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system

At that point we can replace it or confirm it is the issue by capping all the lines coming off of it and see if the pedal goes to the floor. Clearly do not try to drive the vehicle as you will have no brakes but if the pedal does not go to the floor then you have an issue in one of the legs of the system.

If it does go to the floor then you have an issue in the master cylinder and it needs replaced.

Hello,

This could be a situation where you will need to bleed the brake system. It sounds like the ABS brake on, off, on, off, on could have produced air bubbles in the system that need to be bled off. I have included the factory OEM testing guide for your vehicle in the diagrams down below. Please go through it and get back to us with what you find out.

Thanks,
Alex
2CarPros

The best suspect is the master cylinder was damaged in the same way we never push the brake pedal more than half-way to the floor when pedal-bleeding with a helper. Given the age of the vehicle, there will be crud and corrosion built up in the lower halves of the bores in the master cylinder where the pistons don't normally travel. Running the pistons over that crud can rip the rubber lip seals resulting in a slowly-sinking brake pedal that often takes two or three days to show up. When the primary seal on just one piston is ripped, the brake fluid behind the good seal has to move the second piston as well as move its fluid out to the wheels. The pedal will be low, but that's why there is still some stopping power.

It isn't real common for this damage to occur when the brake fluid is under high pressure, but it can happen. This damage occurs much more commonly during pedal-bleeding where there is no real pressure in front of the primary seals.

Most people bleed at the wheels when replacing the master cylinder, but that is not necessary, and it can add another chapter of frustration to the story. Any air sent down the lines will become trapped in the ABS hydraulic controller. You'll need a scanner to bleed that air out. It commands the computer to open two valves so those chambers can be bled. On brands other than Ford, loosen the soft steel line nuts at the master cylinder, unbolt the master cylinder and slide it forward, away from the power booster, then use it as a handle to bend the lines upward a little. That prevents brake fluid from running out of them. Remove the master cylinder. Once the new master cylinder is bench-bled, install the lines, then push it down to bend the lines back to normal. Bolt the master cylinder to the power booster.

Ford products often have four steel lines coming out of the master cylinder. That makes it impossible to bend all of them upward, but the rest of the procedure still works. With the new master cylinder installed, loosen one of the line nuts about half a turn, then have a helper slowly push the brake pedal no more than half way to the floor. The new master cylinder won't be damaged by pushing the pedal too far because no corrosion has built up in it yet, but it's a good practice to have your helper get used to. Snug the line nut, then holler to your helper to quickly release the pedal. Loosen the nut again, then have him push the pedal slowly again. It should take about 15 seconds to push the pedal half way to the floor. If you still see any air bubbles sneaking out, do that a third time. Repeat the procedure for each of the other lines.

By pushing the pedal slowly, fluid gets pushed down the lines, but the air has time to float back up. When releasing the pedal quickly, the fluid rushing back up to the reservoir washes any remaining air bubbles up there with it.

On a few occasions I've had a brake pedal that was a little low at first, but by just driving the vehicle and sitting at red lights with the brakes applied, it never took more than a few miles for the last few air bubbles to work their way out to the reservoir. There's no way air can make its way down to the wheels, so there's no need to bleed at them.

Hi guys. I take issue with one of Ford's instructions, and I should have added it in my reply. We never fill the brake fluid reservoir unless it's during part of a complete brake job that included rebuilding or replacing the calipers. If the fluid level was low previously, where did it go? There was either a leak, or the pads are worn down. As the pads wear, the pistons move out of the caliper housings, and brake fluid takes up the space behind them. Today, with relatively little caliper trouble, it is common to just push the pistons back in to make room for the new pads. Doing that pushes that brake fluid back up into the reservoir. If a do-it-yourselfer filled the reservoir previously, there is going to be a huge mess of brake fluid spilled over that eats paint. That's why we never top off brake fluid during other routine services such as oil changes.

If you are not losing brake fluid through an external leak, the typical cause is an internal leak in the master cylinder. Fluid is bypassing the rubber lip seals rather than getting pushed down to the wheels. The fix is to replace the master cylinder and bleed the system of air. Here are two articles that do a better job of explaining the procedure:

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

If you do this yourself, there is a trick that can make bleeding much easier. It is a little more involved on Fords that have four steel lines leaving the master cylinder, but it works really well on other brands with just two steel lines. Once the new master cylinder is bench-bled and installed on the car, loosen one or more of the line nuts about a quarter turn, then have a helper push the brake pedal very slowly about half way to the floor. That should take about fifteen seconds. You will see air bubbles spit out by the loosened line nuts. Snug those nuts, then holler to the helper to quickly release the pedal. Repeat that until no air bubbles come out, then do that to all the remaining lines.

By pushing the pedal slowly, any air that does still go down the line will float back up. By releasing the pedal quickly, any trapped air bubbles will wash into the reservoir with the brake fluid that is rushing back. By doing this, it is rare to need to bleed at the wheels.

Throughout all this, be extremely careful to not get any hint of petroleum product in the brake fluid. That includes engine oil, power steering fluid, transmission fluid, axle grease, or penetrating oil. Professionals even wash their hands with soap and water to avoid contaminating parts with fingerprint grease. Keep the covers on the reservoir and can of brake fluid as much as possible. Brake fluid absorbs moisture out of the air and that promotes corrosion and lowers the fluid's boiling point. A lowered boiling point can lead to one form of brake fade when the fluid gets hot.