No pressure at brakes they go to the floor why?

Tiny
DUANE STORM SHAW
  • MEMBER
  • 2012 FORD FUSION
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
Have installed new master cylinder two times, left rear caliper two times and a ABS pump and still no pressure at rear brakes.
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Sunday, February 2nd, 2020 AT 8:55 PM

26 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good morning,

Did you bench bleed each master cylinder you replaced?

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

what was the original issue that made you replace these parts?

The ABS has to be bled. That will require a scan tool to open the valves inside the unit to allow fluid flow to the rear wheels.

Roy
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Monday, February 3rd, 2020 AT 4:23 AM
Tiny
DESHAW1970
  • MEMBER
Originally had no brakes and pedal was at the floor. Left rear caliper had a blown out piston installed new rear rotors and pads, used scan tool to auto bleed and did a pressure bleed still no brake pressure. Installed new master cylinder, used scan tool and still no pressure. Then installed ABS pump, used scan tool and still no pressure. Repeating the same process with new parts again, same results. Master cylinder was bench bled, checked for possible lines being crossed at master cylinder, checked brake lines and bleeder valves for blockage and nothing.
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Monday, February 3rd, 2020 AT 5:51 AM
Tiny
ASEMASTER6371
  • EXPERT
Okay, got it.

Try this:

Use vice grips and clamp off the brake hoses. Clamp them all off. Then see if you have a pedal. If you do have a pedal, then release one clamp at a time until the pedal goes bad. That is the area of failure.

Try this and see what happens.

Roy
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Monday, February 3rd, 2020 AT 5:59 AM
Tiny
BMDOUBLE
  • EXPERT
This system absolutely has to be bled with a pressure bleeder! Otherwise you will waste your time trust me! The pressure bleeder has to be set to 30-50 psi and the parking brake needs to be applied 5 times if the rear calipers have the integral parking brake design. I've also included a picture of the sequence that it need to be bled in.
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Monday, February 3rd, 2020 AT 7:26 AM
Tiny
DESHAW1970
  • MEMBER
I've done that left rear with second new caliper still has no pressure. I've even blown brake fluid back with pressure through the bleeder valve to check for a blockage and still no pressure.
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Monday, February 3rd, 2020 AT 11:23 AM
Tiny
ASEMASTER6371
  • EXPERT
Did you do the clamp off on the hoses?

Roy
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Monday, February 3rd, 2020 AT 2:45 PM
Tiny
DESHAW1970
  • MEMBER
Will try the clamps in the morning, but yes both master cylinder where bench bled. Yes, have bleed the ABS pump. Yes, have used scan tool multiple times for bleeding ABS pump.
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Monday, February 3rd, 2020 AT 3:03 PM
Tiny
ASEMASTER6371
  • EXPERT
I read all that already.

Do the clamps ad let me know?

Roy
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Monday, February 3rd, 2020 AT 3:05 PM
Tiny
DESHAW1970
  • MEMBER
Okay, thank you.
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Monday, February 3rd, 2020 AT 3:06 PM
Tiny
ASEMASTER6371
  • EXPERT
You are welcome.

Always glad to help.

Roy
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Monday, February 3rd, 2020 AT 3:07 PM
Tiny
LUIS GERARDO SANCHEZ
  • MEMBER
  • 2011 FORD FUSION
  • 2.5L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 120,000 MILES
Brakes were working fine prior to me replacing the pads, everything went on just as it came off for all pads, after bleeding though, I was only able to get pressure from front driver side and back passenger, when trying bleed the other two wheels pedal doesn't follow through as it should, brake pedal is now hitting the floor. I don't know where the problem may be if its a caliper problem for each wheel or something causing the line to not have the proper pressure since they are diagonally?
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

I would suspect there is air in the lines. These guides can help you fix it.

https://youtu.be/w7gUsj2us0U

and

https://youtu.be/WDxvEQrMkBg

and

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

Please run down these guides and report back.

As far as bleeding, you can't do it on this vehicle in a traditional way. It requires pressurized bleeding. Here are the directions. The attached pics correlate with these directions. Note that the brake pedal going to the floor is likely the result of air in the system. However, the master cylinder itself may have failed internally if the pedal has gone to the floor.

Brake System Bleeding

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: Due to the complexity of the fluid path within the hydraulic system, it is necessary to pressure bleed the system.

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.

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.

Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
LUIS GERARDO SANCHEZ
  • MEMBER
I was able to find a vacuum bleeder since they didn't have a pressure bleeder at my local AutoZone. When I try bleeding the rear left caliper it doesn't allow me to squeeze for higher PSI after opening the screw as if something is blocking its path.
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
The pathways for the brake fluid are not typical and can be restrictive. Do you have the scan tool needed to set it up for bleeding?

In all honesty, I don't know if a vacuum pump will do the job.

Let me know.

Joe
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
CARADIODOC
  • EXPERT
Please allow me to add a few comments of value. Part of this sounds exactly like the problem often encountered on GM front-wheel-drive cars. Most front-wheel-drive vehicles use a split-diagonal hydraulic system for the brakes in which the left front and right rear are on the same circuit. GM uses a valve in the master cylinder that trips when there's an external leak. That valve blocks further fluid flow to those two wheels. It also trips from improper bleeding procedures, in this case, either using a helper to push the brake pedal, or the pedal got pushed too far.

JACOBANDNICKOLAS is right that there was no need to bleed the system. If the reservoir was never allowed to run empty, and no parts in the hydraulic system were replaced, there should be no air in the system now. Referring back to that valve in the master cylinder that GM uses, this may have started with the pad replacement. To fit them in, you had to retract the pistons into the caliper housings. Once everything was reassembled, it was necessary to pump the brake pedal multiple times to run those pistons back out to adjust them. That's for the front calipers. You didn't say if you replaced the front or rear pads. Rear calipers usually require a special tool to retract the pistons, then they have to be adjusted later by cycling the parking brake. If you don't do that, they will never self-adjust like the front ones do, and you'll always have a low and soft brake pedal.

When the brake pedal is pumped to adjust the front calipers, professionals will never push it further than half-way to the floor, in part to prevent tripping that valve in the master cylinder, but more importantly, to prevent damaging the master cylinder. That damage is not from the design of the system. It is due to crud and corrosion that build up in the lower halves of the bores in the master cylinder where the pistons don't normally travel. Running the pedal all the way to the floor runs the pistons and their rubber lip seals over that crud and can rip them. That results in a slowly sinking brake pedal, and that often doesn't show up until two or three days later.

If Ford is using a valve in the master cylinder like GM uses, there is only one way I've found to reset it. That is by loosening the cap on the reservoir, going to either of the wheels that won't flow any fluid, open that bleeder screw, and give it a short, quick burst of compressed air. The goal is to keep that burst small enough to avoid sending air up the line which will just have to be bled out again. All that is needed is to push enough brake fluid back to reset the valve and unblock the ports.

Some mechanics will tell you that valve will not be tripped if you bleed the wheels in a certain order, and even some service manuals say that too, but that can't be true. If it was, that valve would not trip if there was a leak in the line going to the first wheel in that sequence. Some brake system specialists start with the left front wheel so they can get one line totally bled right away. Some will start with the right rear so they get the longest line done first. I always start with the wheel I'm standing closest to. I loosen the cap on the reservoir so vacuum won't build up as the fluid leaves. That vacuum will stop the fluid from flowing freely on its own. I open all four bleeder screws, then let the system gravity-bleed. No helper needed, and at this point I don't touch the brake pedal. This procedure is only necessary after the calipers or wheel cylinders have been rebuilt or replaced. It also works for just one wheel after a rusted steel line or popped rubber flex hose has been replaced. There's no need to bleed the other three wheels.

Once fluid starts dripping from a wheel, I close that bleeder screw. After all four have started flowing fluid and the bleeder screws are all closed, I push the brake pedal about one inch by hand, multiple times, to wash any sticking air bubbles into the wheel cylinders and calipers, then I open each bleeder screw once more for a few seconds to let those air bubbles pop out.

When you have to run the pistons out of the caliper housings to adjust them, be careful to not push the brake pedal more than half-way to the floor. Besides the possibility of tripping the valve or ripping the rubber lip seals, there is also a "pressure-differential" valve in the combination valve assembly under the master cylinder on cars that don't have anti-lock brakes. Ford added to the misery by not making that a spring-loaded valve, as it is on all other car brands. That valve trips one of the switches that turns on the red "Brake" warning light on the dash. On other brands, that valve often sticks, but can be reset by just a good hard push on the brake pedal, after the leak has been repaired. On Fords, resetting that valve can be very tiring and frustrating, so it's best to avoid tripping it in the first place.

All car manufacturers recommend replacing the brake fluid periodically due to the moisture that gets absorbed into it, but very few of us actually do that when the system is so reliable after being ignored for years. Gravity'bleeding works fine for that too, but it is slow. You can speed it up by pushing the brake pedal, but again, don't push it more than half-way to the floor, and don't allow the reservoir to run empty.
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
RANDY REINY REINFELDT
  • MEMBER
  • 2010 FORD FUSION
  • 2.5L
  • 2WD
  • AUTOMATIC
  • 145,000 MILES
I recently replaced the ABS pump/module and master cylinder with salvage yard parts on the listed above it is the SEL model. Bled the system and bled the ABS pump with scanner and still no brake pedal pressure.
ABS light is on now.
Is it possible the booster is bad?
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi Randy and thanks for using 2CarPros.com Even if the booster is bad, you should still have a pedal. If the pedal is going to the floor, review this link and see if anything of the items discussed could be an issue for you. My biggest concern is that you have a used master cylinder. There is a chance it is bad even though you were told differently.

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

I did some research for you and found the following test from Alldata:

Component Tests

Brake Master Cylinder - Bypass Condition

Disconnect the brake tubes from the master cylinder.
Plug the outlet ports of the master cylinder.
Note: Make sure the outlet port plugs do not show signs of leakage.
Lightly apply the brakes and hold for 10 seconds. Release the brakes and then reapply with heavy force. If brake pedal height cannot be maintained, the brake master cylinder has an internal leak and a new brake master cylinder must be installed.

This will at least indicate if the master cylinder is bad. Keeping in mind, if there are no leaks, you should get SOME pedal.

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

Check out the diagrams (Below). Please let us know what happens.
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
KELLYKUL91
  • MEMBER
  • 2009 FORD FUSION
  • V6
  • 2WD
  • AUTOMATIC
  • 125,000 MILES
The brake pedal goes to the floor. We replaced a caliper where there was a leak on the driver's rear. Bled brakes. The driver's rear and passenger front have little to now fluid come out when we bleed. Replaced master cylinder and bled brakes. Still having same issue. Cannot find a leak anywhere else.
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
BMDOUBLE
  • EXPERT
I just helped someone with this problem. When you have a caliper blow out on these cars, the absolute best way to bleed them is with a pressure bleeder mounted on the reservoir at 30 psi to overcome the pressure differential valve. Some people claim that they had success vacuum bleeding these systems but I pressure bleed.
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Monday, March 29th, 2021 AT 10:26 AM (Merged)
Tiny
2CARPROS-ARCHIVES
  • MEMBER
  • 2009 FORD FUSION
  • 150,000 MILES
Just replaced pads and rotors all 4 wheels, brakes are now spongy and soft, have to pump them to get them to work properly. What to do next?
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Monday, March 29th, 2021 AT 10:27 AM (Merged)

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