Soft pedal - brakes go to the floor?

It sounds like the bearing hubs are going out forcing the brake pad back into the caliper. here is a video on how to change them out:

https://youtu.be/ZgiPRG6jffc

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

Hi,

How were the brakes bleed after the work was done? Here is a link that shows how to bleed and flush a system. Since you replaced the lines and master cylinder, there should be no reason to flush it. However, take a look through the bleeding procedure to confirm you did it the same way.

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

Let me know.

Joe

Hi,

We are not permitted to reply on the phone. I'm sorry. Listen, are you getting fluid from each wheel when you bleed them? Have you started from the wheel furthest away from MC (RR, LF, RF, LF)? Also, there are two options when it comes to rear brakes, disc or drum. Are you sure the rear brakes are properly adjusted? If everything I mentioned is good, you still have air in the system. You will need to perform an automated bleed procedure which requires a scan tool. I suspect there is air in the abs.

Here are the directions which start the same as traditional bleeding. However, at step 10 is where the computer has to do its job. Since you have some pedal, this is my first suspect.

__________________________________________________

2000 Chevy Truck K 2500 Truck 4WD V8-6.0L VIN U
Automated Bleed Procedure
Vehicle Brakes and Traction Control Hydraulic System Brake Bleeding Service and Repair Procedures Automated Bleed Procedure
AUTOMATED BLEED PROCEDURE
Important:
Use the two-person bleed procedure under the following conditions:
- Installing a new Electro-Hydraulic Control Unit (EHCU) or new Brake Pressure Modulator Valve (BPMV).
- Air is trapped in the valve body
Do not drive the vehicle until the brake pedal feels firm.
Do not reuse brake fluid that is used during bleeding.
Use the vacuum, the pressure and the gravity bleeding procedures only for base brake bleeding.

Two Person Procedure

1. Raise the vehicle in order to access the system bleed screws.
2. Bleed the system at the right rear wheel first.
3. Install a clear hose on the bleed screw.
4. Immerse the opposite end of the hose into a container partially filled with clean DOT 3 brake fluid.
5. Open the bleed screw 1/2 to one full turn.
6. Slowly depress the brake pedal. While the pedal is depressed to its full extent, tighten the bleed screw.
7. Release the brake pedal and wait 10 - 15 seconds for the master cylinder pistons to return to the home position.
8. Repeat the previous steps for the remaining wheels. The brake fluid which is present at each bleed screw, should be clean and free of air.
9. This procedure may use more than a pint of fluid per wheel. Check the master cylinder fluid level every four to six strokes of the brake pedal in order to avoid running the system dry.
10. Press the brake pedal firmly and run the Scan Tool Automated Bleed procedure (all except diesels above 15,000 GVW) once, or run the Function Test (diesels above 15,000 GVW) four times. Release the brake pedal between each test.
11. Bleed all four wheels again using Steps 3 - 9. This will remove the remaining air from the brake system.
12. Evaluate the feel of the brake pedal before attempting to drive the vehicle.
13. Bleed the system as many times as necessary in order to obtain the appropriate feel of the pedal.

_______________________________________

Let me know if that helps.

Joe

Good evening.

Yes, the master cylinder can be bad. The seals internally may not be holding pressure and allowing the fluid to bypass instead of building pressure.

Do you have ABS?

Roy

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

Important:
Use the two-person bleed procedure under the following conditions:
- Installing a new Electro-Hydraulic Control Unit (EHCU) or new Brake Pressure Modulator Valve (BPMV).
- Air is trapped in the valve body
Do not drive the vehicle until the brake pedal feels firm.
Do not reuse brake fluid that is used during bleeding.
Use the vacuum, the pressure and the gravity bleeding procedures only for base brake bleeding.

Two Person Procedure

1. Raise the vehicle in order to access the system bleed screws.
2. Bleed the system at the right rear wheel first.
3. Install a clear hose on the bleed screw.
4. Immerse the opposite end of the hose into a container partially filled with clean DOT 3 brake fluid.
5. Open the bleed screw 1/2 to one full turn.
6. Slowly depress the brake pedal. While the pedal is depressed to its full extent, tighten the bleed screw.
7. Release the brake pedal and wait 10 - 15 seconds for the master cylinder pistons to return to the home position.
8. Repeat the previous steps for the remaining wheels. The brake fluid which is present at each bleed screw, should be clean and free of air.
9. This procedure may use more than a pint of fluid per wheel. Check the master cylinder fluid level every four to six strokes of the brake pedal in order to avoid running the system dry.
10. Press the brake pedal firmly and run the Scan Tool Automated Bleed procedure (all except diesels above 15,000 GVW) once, or run the Function Test (diesels above 15,000 GVW) four times. Release the brake pedal between each test.
11. Bleed all four wheels again using Steps 3 - 9. This will remove the remaining air from the brake system.
12. Evaluate the feel of the brake pedal before attempting to drive the vehicle.
13. Bleed the system as many times as necessary in order to obtain the appropriate feel of the pedal.

Good afternoon

Was this an issue prior to the repair? This guide 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 this guide and report back.

Did you bleed the ABS with a scan tool? There is an automated brake bleeding procedure for the ABS. Without a scan tool, you will have this issue.

Did you check the master cylinder to be sure it is putting out pressure?

Roy

AUTOMATED BLEED PROCEDURE
Important:
Use the two-person bleed procedure under the following conditions:
- Installing a new Electro-Hydraulic Control Unit (EHCU) or new Brake Pressure Modulator Valve (BPMV).
- Air is trapped in the valve body
Do not drive the vehicle until the brake pedal feels firm.
Do not reuse brake fluid that is used during bleeding.
Use the vacuum, the pressure and the gravity bleeding procedures only for base brake bleeding.

Two Person Procedure

1. Raise the vehicle in order to access the system bleed screws.
2. Bleed the system at the right rear wheel first.
3. Install a clear hose on the bleed screw.
4. Immerse the opposite end of the hose into a container partially filled with clean DOT 3 brake fluid.
5. Open the bleed screw 1/2 to one full turn.
6. Slowly depress the brake pedal. While the pedal is depressed to its full extent, tighten the bleed screw.
7. Release the brake pedal and wait 10 - 15 seconds for the master cylinder pistons to return to the home position.
8. Repeat the previous steps for the remaining wheels. The brake fluid which is present at each bleed screw, should be clean and free of air.
9. This procedure may use more than a pint of fluid per wheel. Check the master cylinder fluid level every four to six strokes of the brake pedal in order to avoid running the system dry.
10. Press the brake pedal firmly and run the Scan Tool Automated Bleed procedure (all except diesels above 15,000 GVW) once, or run the Function Test (diesels above 15,000 GVW) four times. Release the brake pedal between each test.
11. Bleed all four wheels again using Steps 3 - 9. This will remove the remaining air from the brake system.
12. Evaluate the feel of the brake pedal before attempting to drive the vehicle.
13. Bleed the system as many times as necessary in order to obtain the appropriate feel of the pedal.

Sounds good. Keep me updated.

Roy

Good deal. Glad it is fixed.

Roy

Good afternoon,

Did you bleed the ABS?

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

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

Roy

Important:
Use the two-person bleed procedure under the following conditions:
Installing a new Electro-Hydraulic Control Unit (EHCU) or new Brake Pressure Modulator Valve (BPMV).
Air is trapped in the valve body
Do not drive the vehicle until the brake pedal feels firm.
Do not reuse brake fluid that is used during bleeding.
Use the vacuum, the pressure and the gravity bleeding procedures only for base brake bleeding.

Two Person Procedure

1. Raise the vehicle in order to access the system bleed screws.
2. Bleed the system at the right rear wheel first.
3. Install a clear hose on the bleed screw.
4. Immerse the opposite end of the hose into a container partially filled with clean DOT 3 brake fluid.
5. Open the bleed screw 1/2 to one full turn.
6. Slowly depress the brake pedal. While the pedal is depressed to its full extent, tighten the bleed screw.
7. Release the brake pedal and wait 10 - 15 seconds for the master cylinder pistons to return to the home position.
8. Repeat the previous steps for the remaining wheels. The brake fluid which is present at each bleed screw, should be clean and free of air.
9. This procedure may use more than a pint of fluid per wheel. Check the master cylinder fluid level every four to six strokes of the brake pedal in order to avoid running the system dry.
10. Press the brake pedal firmly and run the Scan Tool Automated Bleed procedure (all except diesels above 15,000 GVW) once, or run the Function Test (diesels above 15,000 GVW) four times. Release the brake pedal between each test.
11. Bleed all four wheels again using Steps 3 - 9. This will remove the remaining air from the brake system.
12. Evaluate the feel of the brake pedal before attempting to drive the vehicle.
13. Bleed the system as many times as necessary in order to obtain the appropriate feel of the pedal.

Can you upload a picture or video of the problem area to get a better understanding? Also, a picture of the master cylinder area to see what type of brake booster you have there.

I live near Pittsburgh, so I am quite used to the hills. But more importantly, rust. Yes, it is common for the brake lines to fail due to rust around here, but if you lost that much fluid, it should have gone down in the master cylinder. If the leak was under the seat, there are only two things it could be, fuel or brake fluid. Without seeing and analyzing the problem, it is hard to say because you are correct saying the fluid should have dropped in the master cylinder. As far as the spongy brake, yes a worn master cylinder can allow brake fluid to bypass the plunger. The easiest way to determine that is to simply put pressure on the brake pedal and hold. If it is bypassing internally, the pedal will slowly go to the floor.

I hope that helps.

PS: If the fuel lines are original, expect them to be next.