Soft brake pedal

[winford hackworth]

I have a 1997 K 1500 brake booster went bad but before booster went bad it still had a soft pedal, when I replaced the booster I had a friend of mine help me bleed the brakes and still have soft pedal when you first hit the brake pedal for the first time the brake light comes on after that you pump them and it will go out been doing some research and from what I understand the ABS has air in the lines also heard to hit a gravel road and make the ABS kick in and then bleed them again any more additional help with this situation we will be greatly appreciated

 

[kennythewelder]

You may need to do a pressure bleed, ans system flush. Watch the video all the way through. It is very detailed.

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[kennythewelder]

Oh and if you havent do so already, you may want to do the NBS MC swap. I took mine off of a 2001 Tahoe. There are some threads on here about doing the MC swap.

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[winford hackworth]

Ok thanks. I didn' know anything about the swap. What' the reasoning of it. And you just replace the master cylinder?

 

[kennythewelder]

The NBS MC had a bigger piston then ours. It firms up the peddle. It is a direct swap, except you need an adapter for the front brake line. Here is the OP on doing the swap. This is an old thread, so the pics may not work.
http://www.gmt400.com/threads/how-to-nbs-master-cylinder-swap-for-firm-brake-pedal.17998/

 

[df2x4]

Before you try anything drastic, take it to a shop with a GM Tech 2 or equivalent bi-directional scan tool that can command the ABS module to open. This will allow you to get all the air out of the system in the easiest, safest way possible.

Alternatively if you really don't want to do that, (Which it seems many people on this site don't for some reason) you can accomplish the same result by slamming on the brakes on gravel and re-bleeding multiple times.

 

[winford hackworth]

Before you try anything drastic, take it to a shop with a GM Tech 2 or equivalent bi-directional scan tool that can command the ABS module to open. This will allow you to get all the air out of the system in the easiest, safest way possible.

Alternatively if you really don't want to do that, (Which it seems many people on this site don't for some reason) you can accomplish the same result by slamming on the brakes on gravel and re-bleeding multiple times.

Ok thanks for input. I'l have to see about that.

 

[winford hackworth]

The NBS MC had a bigger piston then ours. It firms up the peddle. It is a direct swap, except you need an adapter for the front brake line. Here is the OP on doing the swap. This is an old thread, so the pics may not work.
http://www.gmt400.com/threads/how-to-nbs-master-cylinder-swap-for-firm-brake-pedal.17998/

Still what about the abs? Seen where you have to have a scan tool to bleed properly

 

[kennythewelder]

I am not saying that df2x4 is wrong, but I have never used a scan tool to bleed my brakes. When I did my MC swap, I just did my bleed the old fashion way. I bench blead the MC, then after the install, I blead it again on the truck, then I started @ the rear passengers wheel. I bleed all wheels 6 times, then started over again with the rear passengers wheel. So I bleed each wheel 12 times. You can see how clear the fluid is in the pic of my MC above. It almost looks like the MC is empty, but it is not. This is also why I posted about the pressure bleed. Some say that the MC swap is not a good idea, as the NBS trucks are rear disc brakes, and they take less pressure. All I can tell you, is that it works well on my 97, and all I did was the MC swap as described above. Oh and my wife bitched the next day because of all of the peddle pumping while helping me bleed my system. The thing I like about these trucks, is that you can still fix them the old way most of the time. They are easy to work on. If you have all of the scan tool to do this, then fine, but I did mine without any scan tool.

 

[winford hackworth]

I am not saying that df2x4 is wrong, but I have never used a scan tool to bleed my brakes. When I did my MC swap, I just did my bleed the old fashion way. I bench blead the MC, then after the install, I blead it again on the truck, then I started @ the rear passengers wheel. I bleed all wheels 6 times, then started over again with the rear passengers wheel. So I bleed each wheel 12 times. You can see how clear the fluid is in the pic of my MC above. It almost looks like the MC is empty, but it is not. This is also why I posted about the pressure bleed. Some say that the MC swap is not a good idea, as the NBS trucks are rear disc brakes, and they take less pressure. All I can tell you, is that it works well on my 97, and all I did was the MC swap as described above. Oh and my wife bitched the next day because of all of the peddle pumping while helping me bleed my system. The thing I like about these trucks, is that you can still fix them the old way most of the time. They are easy to work on. If you have all of the scan tool to do this, then fine, but I did mine without any scan tool.

Ok maybe I didn't bleed enough, the brakes was soft before I changed the booster, but know they seem more so and the light comes on. Thanks for the info