not as good of brake as i think they should be

[knagel]

06 2500hd chevy duramax reg cab. Here is the story. Brake line blew(rusted). Dad drove it for a while like that before he said anything. We replaced the lines and bled. Decent flow at all 4 corners. Pedal doesnt feel like it did before the line blew. Tried gravity bleed, tried vac bleed, tried engine running pedal bleed. Decided to replace master cyl, bench bled and installed. Same thing.

If I had to make an assumption, it feels like it being a 2 stage master cyl that the 1st stage is soft and 2nd is normal. Im guessing the 1st stage is front brakes and 2nd is rear? If you do an ABS bleed thru the scan tool you can hear the motor and feel it moving the pedal up and down through out the test.

We have even tried bleeding each caliper while doing the test in hopes if there was air trapped in the ABS module it would move out.

Any thoughts on how to proceed? The truck stops fine. Doesn't really lock up the brakes though and sure enough not to activate the ABS. The reason I am asking all this is it just doesnt feel like the other duramaxs we have in this year group.

Thanks,

Kevin

 

[jlawles2]

Should be one stage for the master cylinder. You may have a bubble stuck somewhere in the system.

You might try pushing the pistons back into the caliper fully then pumping the brakes back hard a couple of times to see if you can get the bubble to move. Rapid fluid movement is what it takes sometimes to get the bubble out.

 

[malibu795]

When I did the brake system on my LMM I had to "bleed the ABS" via controller.

If you don't have state s
Inspection BS and can delete the ABS pump/module
There's this

ABS Delete Block for GM 99-06 Trucks - Atomic Fabrication

Billet aluminum ABS delete block used to delete the ABS unit on 99-06 trucks with factory lines. See below for more information

atomicfabandperformance.com

 

[badmatt]

As stated above I had to do an ABS bleeding procedure via my scan tool, made the world of difference.