Brake bleeding instructions - when the car is off or while it is running?

Hey TIMBRIGHT,

I will attach the instructions to replace the rear caliper.

They advise you deactivate the park brake before doing this so I will also add the procedure for this. You will need to reactivate after fitting.

For bleeding I will also add the section on brake bleeding, it looks like you just need to activate the park brake a few times to remove all the air from the caliper. You may need to start the engine to do this but it should work with just ignition on.

The bleeding part you do not need the engine on for.

Hope this is everything you need but any further questions please do not hesitate to ask.

Regards, Joe

That has to do with the power assist. Here is a video and guide below to help you bleed the brake system correctly.

https://youtu.be/w7gUsj2us0U

and

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

and

https://youtu.be/WDxvEQrMkBg

Please run down these guides and report back.

The bigger problem is you need the power assist when pedal-bleeding with a helper. That method is rarely used by a professional. We use gravity-bleeding where the bleeder screws are opened, the reservoir cap is loosened, then we wait for brake fluid to show up at the wheels. Once all the bleeder screws are closed, "irritate" the brake pedal by hand a little to wash any remaining bubbles into the calipers and wheel cylinders. Open each bleeder screw once more to burp those few remaining bubbles. Add brake fluid to the reservoir as appropriate, and you're done.

Pedal-bleeding can be used but the mistake most people make is the helper pushes the pedal all the way to the floor. No professional will ever do that. Crud and corrosion build up in the lower halves of the bores where the pistons don't normally travel in the master cylinder. Pushing the pedal over half way runs the rubber lip seals over that crud and can rip them. This shows up as a slowly-sinking brake pedal, and it often takes two or three days to show up. The fix for that is to replace the master cylinder.

Dandy. That's the second Fusion rear caliper problem this week. Happy to hear you solved it.

Good morning,

There is no other way to bleed it except with a scan tool. The scan tool opens all the solenoids and allows the air out of the system.

Roy

Hydraulic Control Unit (HCU) Bleeding

WARNING: Do not use any fluid other than clean brake fluid meeting manufacturer's specification. Additionally, do not use brake fluid that has been previously drained. Following these instructions will help prevent system contamination, brake component damage and the risk of serious personal injury.

WARNING: Carefully read cautionary information on product label. For EMERGENCY MEDICAL INFORMATION seek medical advice. In the USA or Canada on Ford/Motorcraft products call: 1-800-959-3673. For additional information, consult the product Material Safety Data Sheet (MSDS) if available. Failure to follow these instructions may result in serious personal injury.

WARNING: Do not allow the brake master cylinder to run dry during the bleeding operation. Master cylinder may be damaged if operated without fluid, resulting in degraded braking performance. Failure to follow this instruction may result in serious personal injury.

NOTICE: Do not spill brake fluid on painted or plastic surfaces or damage to the surface may occur. If brake fluid is spilled onto a painted or plastic surface, immediately wash the surface with water.

NOTE: When any part of the hydraulic system is disconnected for repair or installation of new components, air can get into the system and cause spongy brake pedal action. This requires bleeding of the hydraulic system after it is correctly connected.

All vehicles

1. Use the Pressure Bleeding procedure to bleed the system. For additional information, refer to Brake System Bleeding.

2. Connect the scan tool and follow the ABS HCU Hydraulic Control Unit (HCU) bleeding instructions.

3. Repeat the Pressure Bleeding procedure to bleed the system.

Hybrid vehicles

4. Following the scan tool instructions, carry out the Multi-Calibration Routine.

The brake system on the Fusion must be pressure bled or else you will chase your tail for days.

Welcome to 2CarPros.

Due to the complexity of the fluid path within the hydraulic system, it is necessary to pressure bleed the system. To make things worse, it requires specific software. Here are the directions:

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2010 Ford Fusion FWD L4-2.5L
Brake System Bleeding
Vehicle Brakes and Traction Control Hydraulic System Brake Bleeding Service and Repair Procedures Brake System Bleeding
BRAKE SYSTEM BLEEDING
Brake System Bleeding

picture 1

picture 2

Pressure Bleeding

WARNING: Do not use any fluid other than clean brake fluid meeting manufacturer's specification. Additionally, do not use brake fluid that has been previously drained. Following these instructions will help prevent system contamination, brake component damage and the risk of serious personal injury.

WARNING: Carefully read cautionary information on product label. For EMERGENCY MEDICAL INFORMATION seek medical advice. In the USA or Canada on Ford/Motorcraft products call: 1-800-959-3673. For additional information, consult the product Material Safety Data Sheet (MSDS) if available. Failure to follow these instructions may result in serious personal injury.

WARNING: Do not allow the brake master cylinder to run dry during the bleeding operation. Master cylinder may be damaged if operated without fluid, resulting in degraded braking performance. Failure to follow this instruction may result in serious personal injury.

NOTICE: Do not spill brake fluid on painted or plastic surfaces or damage to the surface may occur. If brake fluid is spilled onto a painted or plastic surface, immediately wash the surface with water.

NOTE: When any part of the hydraulic system has been disconnected for repair or installation of new components, air can get into the system and cause spongy brake pedal action. This requires bleeding of the hydraulic system after it has been correctly connected.

NOTE: Due to the complexity of the fluid path within the rear integral parking brake calipers, it is necessary to press and release the parking brake during the bleed procedure.

NOTE: The Hydraulic Control Unit (HCU) bleeding procedure must be carried out if the HCU or any components upstream of the HCU are installed new.

All vehicles

1. Clean all the dirt from around the brake fluid reservoir cap and remove the cap. Fill the brake master cylinder reservoir with clean, specified brake fluid.

Pic 3

2. NOTE: Master cylinder pressure bleeder adapter tools are available from various manufacturers of pressure bleeding equipment. Follow the instructions of the manufacturer when installing the adapter.

Install the bleeder adapter to the brake master cylinder reservoir and attach the bleeder tank hose to the fitting on the adapter.

3. NOTE: Make sure the bleeder tank contains enough specified brake fluid to complete the bleeding operation.

Open the valve on the bleeder tank.

- Apply 207-345 kPa (30-50 psi) to the brake system.

4. Remove the RH rear bleeder cap and place a box-end wrench on the bleeder screw. Attach a rubber drain tube to the RH rear bleeder screw and submerge the free end of the tube in a container partially filled with clean, specified brake fluid.

5. Loosen the RH rear bleeder screw. Leave open until clear, bubble-free brake fluid flows, then tighten the RH rear bleeder screw.
- Press and release the parking brake 5 times.

- Repeat until clear, bubble-free fluid comes out.

6. Tighten the RH rear bleeder screw to specifications, refer to Specifications. Remove the rubber hose and install the bleeder screw cap.

7. Repeat Steps 4 through 6 for the LH rear brake caliper.

8. Remove the RH front bleeder cap and place a box-end wrench on the bleeder screw. Attach a rubber drain tube to the RH front bleeder screw and submerge the free end of the tube in a container partially filled with clean, specified brake fluid.

9. Loosen the RH front bleeder screw. Leave open until clear, bubble-free brake fluid flows, then tighten the RH front bleeder screw.

10. Tighten the LH rear bleeder screw to specifications, refer to Specifications. Remove the rubber hose and install the bleeder screw cap.

11. Repeat Steps 8 through 10 for the LH front brake caliper.

12. Close the bleeder tank valve and release the pressure. Remove the tank hose from the adapter and remove the adapter. Fill the reservoir with clean, specified brake fluid and install the reservoir cap.

Hybrid vehicles

13. NOTE: On hybrid vehicles, the brake booster push rod has an elongated slot that attaches to the brake pedal with a clevis pin. The elongated slot allows for a small amount of pedal travel (free play) to occur without the brake pedal applying pressure on the booster push rod. When performing a bleed procedure, it is important to push the pedal through the air gap, so that the clevis pin is contacting the brake booster push rod. Except when required by the scan tool, the ignition key must remain off during the bleed procedure to allow minimal force required to push through the gap.

With the ignition off, press the brake pedal through the gap to seat the clevis pin against the brake booster push rod and then confirm the pedal is firm.

- If the brake pedal is spongy (soft), repeat the Pressure Bleeding procedure to remove any remaining air from the system.

Non-hybrid vehicles

14. Apply the brakes several times to verify correct brake operation.
- If the brake pedal is spongy (soft), repeat the Pressure Bleeding procedure to remove any remaining air from the system.

Hydraulic Control Unit (HCU) Bleeding

WARNING: Do not use any fluid other than clean brake fluid meeting manufacturer's specification. Additionally, do not use brake fluid that has been previously drained. Following these instructions will help prevent system contamination, brake component damage and the risk of serious personal injury.

WARNING: Carefully read cautionary information on product label. For EMERGENCY MEDICAL INFORMATION seek medical advice. In the USA or Canada on Ford/Motorcraft products call: 1-800-959-3673. For additional information, consult the product Material Safety Data Sheet (MSDS) if available. Failure to follow these instructions may result in serious personal injury.

WARNING: Do not allow the brake master cylinder to run dry during the bleeding operation. Master cylinder may be damaged if operated without fluid, resulting in degraded braking performance. Failure to follow this instruction may result in serious personal injury.

NOTICE: Do not spill brake fluid on painted or plastic surfaces or damage to the surface may occur. If brake fluid is spilled onto a painted or plastic surface, immediately wash the surface with water.

NOTE: When any part of the hydraulic system is disconnected for repair or installation of new components, air can get into the system and cause spongy brake pedal action. This requires bleeding of the hydraulic system after it is correctly connected.

All vehicles

1. Use the Pressure Bleeding procedure to bleed the system. For additional information, refer to Brake System Bleeding.

2. Connect the scan tool and follow the ABS HCU Hydraulic Control Unit (HCU) bleeding instructions.

3. Repeat the Pressure Bleeding procedure to bleed the system.

Hybrid vehicles

4. Following the scan tool instructions, carry out the Multi-Calibration Routine.

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Let me know if I can help in any way.

Joe

This is dandy information, but let me add a few thoughts. Both of you replaced the master cylinder so this warning doesn't apply, but it does to anyone else bleeding brakes with an old master cylinder. After about a year or so, crud and corrosion build up in the lower halves of the bores where the pistons don't normally travel. When you run the brake pedal all the way to the floor, the rubber lip seals are run over that crud, and that can rip them. That results in a slowly-sinking brake pedal, and that often takes two or three days to show up. For that reason, any time a car comes in where the driver was surprised by a sudden leak as from a ruptured rubber hose, or when we're informed the owner already tried bleeding the system, we always include a rebuilt mater cylinder in the repair estimate so we're covered in case that additional cost becomes necessary. A lot of shops automatically replace the master cylinder right away rather than risk the liability and angry customer if it fails a few days later.

The standard warning is to never push a brake pedal all the way to the floor. I never use pedal-bleeding with a helper any more, since the late '80s. Gravity-bleeding has always done the job.

The second issue when replacing a master cylinder is there is rarely a need to bleed at the wheels. The steel lines come out the side of the master cylinder for an inch or two, then bend and go down. Except for those coupe of inches, how is air going to get in the rest of the lines? All that bleeding at the wheels accomplishes is forcing air to go into the lines and the ABS hydraulic controller. That is when the real frustration starts.

There's no valves in the hydraulic controller that need power applied to open and let brake fluid flow. If that were the case, you'd have no brakes when a major electrical failure occurred, and you'd have an unusually-high and hard brake pedal since the fluid flow was blocked. You can be sure there would be lawsuits over that, and the politicians would get involved. Rather, when anything electrical happens, and when no ABS activation is required, the path for brake fluid flow is wide open like normal, and the brakes will work the same as they did on all non-ABS-equipped vehicles for the last 100 years. Gravity-bleeding would eventually expel the air in the lines, at the bleeder screws at the wheels.

The problem is there's chambers that fill with brake fluid inside the hydraulic controller. When ABS activation is called for, valves push that fluid out, then release it back, to pulse brake fluid pressure to a wheel. It's those chambers that need to have the air expelled. To do that requires opening some valves, and that can only be done two ways. One is to drive the vehicle fast enough to allow ABS activation, typically 3 to 9 mph, and the bleeder screws have to be open at the wheels to give the fluid a place to go. Obviously that is not a practical procedure since you can't run fast enough alongside the car. This is why we have to do the procedure with a scanner. That has a procedure for doing the bleeding on the hoist. Most vehicles require bleeding at just two wheels, and it takes less than ten seconds.

All of this can be avoided when replacing the master cylinder, although Ford has complicated the issue by using four steel lines at their master cylinders instead of just two. You'll still usually find only two lines when the car has ABS. Bench-bleed the replacement master cylinder like normal. Loosen the soft metal line nuts while the old master cylinder is still bolted to the power booster. Unbolt the master cylinder and slide it forward off the mounting studs. At this point, to speed up the process a little, I use the master cylinder as a handle to bend the steel lines up a little. That will prevent the brake fluid from running out of that first inch of line. This is where you can only do that on two of the four lines on Fords. Now remove the lines from the old master cylinder.

Do your bench-bleeding line normal, then install the lines onto it. Snug the line nuts just enough to prevent loss of fluid. Push the master cylinder down to bend the lines back to their normal shape, then bolt it to the power booster.

At this point there are just a few air bubbles in the lines and they're all right next to the ports in the master cylinder. Loosen one of the line nuts about a quarter turn, then have a trusted helper slowly push the brake pedal no more than half way to the floor. It should take about 15 seconds to do that. You'll see air bubbles coming out by the line nut. Tighten that nut, then holler to your helper to release the pedal quickly. Loosen the nut, then do that again, and possibly a third time, until no more air bubbles come out. Repeat that for the other line, and you're done.

By pushing the brake pedal slowly, brake fluid gets pushed down the lines, like normal, and the air has time to float back up. When the pedal is released quickly, the fluid rushing back washes any air along with it back up into the reservoir. Even if a few tiny air bubbles remain in the lines, you know they aren't going to go down to the wheels or the hydraulic controller. Air is lighter than brake fluid. It won't take long while idling at a stop light with the brakes applied and the car is vibrating, for that air to work its way out and into the reservoir.

Thank you, Lklafter1, for adding your information. Some engineers seem to be fulfilled when they make things as unnecessarily-complicated as possible. Hopefully this will help others researching this topic.

It sounds like the initial problem was caused right after the pads were replaced. Gravity-bleeding would have been sufficient after loosening the bolt for the brake hose. All that was needed was to open the bleeder screw for half a minute, and briefly loosen the cap on the brake fluid reservoir so vacuum does not build up that would impede fluid flow. The real problem comes from having to push the pistons into the calipers to make room for the new, thicker pads. Once the job is completed, you need to pump the brake pedal repeatedly until the pistons are run back out to adjust them. Most do-it-yourselfers and inexperienced mechanics push the brake pedal all the way to the floor. That is what damages the master cylinder. This can also happen when a driver is surprised by a sudden leak. For that reason, when estimating the cost of repairing a leaking line or hose, most reputable shops will automatically include the cost of a new master cylinder.

Crud and corrosion build up in the lower halves of the bores where the pistons do not normally travel. Pushing the pedal over half way runs the rubber lip seals over that crud and can rip them. That results in a slowly-sinking brake pedal, and that often does not show up for two or three days.

There is no way air could have gotten into the lines until the master cylinder was disconnected. I have a trick to replace a master cylinder without the need to bleed at the wheels, but it does not work as well on Fords that have four steel lines leaving the master cylinder. Once the new master cylinder was installed, there would be some air at the top of the lines, then, pedal-bleeding with a helper, and possibly even when gravity-bleeding, that air would become trapped in the anti-lock brake hydraulic controller. At that point you will always have a mushy brake pedal. You will need a scanner to command the ABS computer to open two valves so those chambers can be bled, then bleed at the two wheels listed on the scanner's display to expel the air.

Just to add some more reference material for this issue.

Here are some guides that will help with this issue.

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

Also, here is some info on bleeding and flushing the brake system.

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

Let's run through this info and report back if there are issues. Thanks

Here is a video and guide below to help you bleed the brake system correctly.

https://youtu.be/w7gUsj2us0U

and

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

and

https://youtu.be/WDxvEQrMkBg

Please run down these guides and report back.

No, the hose is around 20 plus 1 hour labor

Roy