I replaced my pads now the brake pedal goes to the floor

If you're not leaking anywhere-and is sinking to the floor-replace the master cylinder,its not coming from the booster.

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 this guide and report back.

You can follow this guide explains is perfectly.

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

You may need a scanner to open the valve in the ABS while bleeding I have seen this problem before.

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help

Cheers

Good afternoon,

Since you have a scan tool, I would do the automated bleed procedure for the ABS module. Sounds like you have air in the ABS module.

Roy

ABS Automated Bleed Procedure

Notice: When adding fluid to the brake master cylinder reservoir, use only Delco Supreme 11, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. The use of any type of fluid other than the recommended type of brake fluid, may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in Service Precautions.

Important: This procedure may be performed on all vehicles EXCEPT those equipped with option code JL4, Vehicle Stability Enhancement System (VSES).

Important: The base hydraulic brake system must be bled before performing this automated bleeding procedure. If you have not yet performed the base hydraulic brake system bleeding procedure, refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Pressure) in Hydraulic Brakes before proceeding.

1. Install a scan tool to the vehicle.
2. Start the engine and allow the engine to idle.
3. Depress the brake pedal firmly and maintain steady pressure on the pedal.
4. Using the scan tool, begin the automated bleed procedure.
5. Follow the instructions on the scan tool to complete the automated bleed procedure. Release the brake pedal between each test sequence.
6. Turn the ignition OFF.
7. Remove the scan tool from the vehicle.
8. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11 GM P/N 12377967 (Canadian P/N 992667) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
9. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Pressure) in Hydraulic brakes.
10. With the ignition OFF, apply the brakes 3-5 times, or until the brake pedal becomes firm, in order to deplete the brake booster power reserve.
11. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
12. If the brake pedal feels spongy, repeat the automated bleeding procedure. If the brake pedal still feels spongy after repeating the automated bleeding procedure inspect the brake system for external leaks. Refer to Brake System External Leak Inspection in Hydraulic Brakes.
13. Turn the ignition key ON, with the engine OFF; check to see if the brake system warning lamp remains illuminated.
14. If the brake system warning lamp remains illuminated, DO NOT allow the vehicle to be driven until it is diagnosed and repaired. Refer to Symptoms - Hydraulic Brakes.
15. Drive the vehicle to exceed 13 kph (8 mph) to allow ABS initialization to occur. Observe brake pedal feel.
16. If the brake pedal feels spongy, repeat the automated bleeding procedure until a firm brake pedal is obtained.

Okay, then you will need a pressure bleeder. That is where you put an adapter on top of the master cylinder and apply air pressure to the fluid. Then open the bleeders one by one until all the air is out.

You have air trapped in the lines and the foot method of bleeding is not enough to get the air out of the system.

Roy

You are welcome.

Always glad to help.

Roy

Good evening,

This sounds like you still have air in the system.

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

When you bled the system, did you use a pressure bleeder? With it being a truck, using someone to push the pedal will not force the air out of the system.

I would rent a pressure bleeder and bleed the system.

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

I also noticed you did not replace the master cylinder. That may be the issue.

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

Roy

Good morning,

Did you bench bleed the master before installing?

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

You most likely have air in the ABS unit. You need a scan tool to do the automated bleed procedure. I attached the procedure for you.

Roy

Change Vehicle Bookmarks Library Request Conversion Calculator Technician's Reference - Collision

brake bleeding
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2003 Chevy Truck C 1500 Truck 2WD V6-4.3L VIN X
ABS Automated Bleed Procedure
Vehicle Brakes and Traction Control Hydraulic System Brake Bleeding Service and Repair Procedures ABS Automated Bleed Procedure
ABS AUTOMATED BLEED PROCEDURE
Antilock Brake System

Repair Instructions

ABS Automated Bleed Procedure

Note: When adding fluid to the brake master cylinder reservoir, use only Delco Supreme 11(r), GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. The use of any type of fluid other than the recommended type of brake fluid may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

Note: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in Cautions and Notices.

Important: This procedure may be performed on all vehicles EXCEPT those equipped with option code JL4, Vehicle Stability Enhancement System (VSES).

Important: The base hydraulic brake system must be bled before performing this automated bleeding procedure. If you have not yet performed the base hydraulic brake system bleeding procedure, refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Pressure) in Hydraulic Brakes before proceeding.

1. Install a scan tool to the vehicle.
2. Start the engine and allow the engine to idle.
3. Depress the brake pedal firmly and maintain steady pressure on the pedal.
4. Using the scan tool, begin the automated bleed procedure.
5. Follow the instructions on the scan tool to complete the automated bleed procedure. Release the brake pedal between each test sequence.
6. Turn the ignition OFF.
7. Remove the scan tool from the vehicle.
8. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11(r) GM P/N 12377967 (Canadian P/N 992667) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
9. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Pressure) in Hydraulic brakes.
10. With the ignition OFF, apply the brakes 3-5 times, or until the brake pedal becomes firm, in order to deplete the brake booster power reserve.
11. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
12. If the brake pedal feels spongy, repeat the automated bleeding procedure. If the brake pedal still feels spongy after repeating the automated bleeding procedure inspect the brake system for external leaks. Refer to Brake System External Leak Inspection in Hydraulic Brakes.
13. Turn the ignition key ON, with the engine OFF; check to see if the brake system warning lamp remains illuminated.
14. If the brake system warning lamp remains illuminated, DO NOT allow the vehicle to be driven until it is diagnosed and repaired. Refer to Symptoms - Hydraulic Brakes in Hydraulic Brakes.
15. Drive the vehicle to exceed 13 kph (8 mph) to allow ABS initialization to occur. Observe brake pedal feel.
16. If the brake pedal feels spongy, repeat the automated bleeding procedure until a firm brake pedal is obtained.

I assume the symptom is the brake pedal goes too far to the floor. If that is what is happening, the best suspect is the master cylinder was damaged. Crud and corrosion builds up in the lower halves of the bores where the pistons do not normally travel. When surprised by a sudden leak, we almost always push the pedal as far as possible, and that runs the rubber lip seals over that crud and can rip them. The same thing happens when do-it-yourselfers pedal-bleed improperly with a helper. Pushing the brake pedal over half way is likely to damage the master cylinder. This does not apply to a master cylinder that is less than about a year old.

Also, if the reservoir was run empty, and the truck has four-wheel-anti-lock brakes, you may need to bleed the system with a scanner. That will allow you to command the computer to open two valves to allow those chambers to be bled. If you have rear-wheel-ABS (RWAL), which used to be more common on trucks, no special procedure is needed when bleeding those vehicles.

If you need to replace the master cylinder and the truck does not have four-wheel-ABS, I can share a trick so you do not have to bleed at the wheels. This also works with ABS if you never let the reservoir run empty so there is no air in the hydraulic controller.