second pump it goes to the floor

Hi,

If the brake pedal goes to the floor, first make sure there are no hydraulic leaks in the brake system. Make sure the brake fluid reservoir is full. If it is, chances are the brake master cylinder is bad.

Take a look through this link:

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

If you find the master cylinder is bad, replacing it isn't too hard of a job. When you get the replacement part, make sure it has a lifetime warranty. That way, you'll never have to pay for it again.

First, here is a link that shows how in general one is replaced. You can use this as a guide.

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

The new brake master cylinder will need bench bled before install. Here is a video that shows how that is done:

https://youtu.be/WDxvEQrMkBg

Here are directions specific to your vehicle. The attached pics below correlate with the directions.

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2006 Hummer H3 L5-3.5L
Master Cylinder Replacement
Vehicle Brakes and Traction Control Hydraulic System Brake Master Cylinder Service and Repair Procedures Master Cylinder Replacement
MASTER CYLINDER REPLACEMENT
Master Cylinder Replacement
Replacement Procedure

pic 1


1. Remove the brake master cylinder reservoir.


pic 2


2. Remove the brake booster inlet hose (2).


pic 3


3. Remove the brake booster outlet pipe (2).


pic 4


4. Remove the accumulator (1).

pic 5


5. Remove the hydraulic brake booster.


pic 6


6. Remove the brake pressure modulator valve (BPMV) (26) from the master cylinder.
7. Remove the brake master cylinder (5).

Installation Procedure


pic 7


1. Install the BPMV (26) on the master cylinder (5).


pic 8


2. Install the hydraulic brake booster.


pic 9


3. Install the accumulator (1).


pic 10


4. Install the brake booster inlet pipe (2).


pic 11


5. Install the brake booster outlet hose (2).


pic 12


6. Remove the brake master cylinder reservoir.

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I hope this helps. Let me know if you have other questions.

Take care and God Bless,

Joe