[StabbinStevem]

Like the title states, I have soft brakes. I have been trying to figure this out on my own for about a year now... Let me tell yall my setup to get us all on the same page.

I have a 1998 Tahoe 2 door with a SAS. It has a Corp. 10 bolt in the front with standard 3/4 ton brakes and a corp 14 bolt(2nd gen) in the rear with a disc conversion that I made up using 2002 2500HD rear rotors and 73-87 front calipers. The master cylinder is stock(new) with the 1.57 piston. All of the stock ABS, Combination, and metering valves have been removed. There is now an adjustable proportioning valve to control the rear brake pressure. Today I bled a new M/C and installed it on the truck. With plugs installed in the ports and the M/C installed It is solid. Once I install the front and rear brake lines, the brakes get soft. No bubbles or anything in the lines. There are zero leaks. It stops well, and will lock up the tires if I mash on it, but I want the pedal feel at least of stock...
Am I asking to much of my brake system? Should I just deal with it? Or am I missing something?

Thanks guys.

 

[SuperStepside]

You usually upgrade to the NBS master cylinder when you convert to rear disc brakes. It may help but to be honest the 96-98 OBS trucks are notorious for having a soft pedal.

 

[StabbinStevem]

I was considering a NBS master cylinder but was doing research and the Piston diameter is 1.456" making it smaller than the 1.57" diameter MC that I already have. Is there an actual design difference that makes it better?

 

[baggeddraged]

every obs I've owned has had soft brakes.

 

[SuperStepside]

The NBS design has a resevoir thats half and half. The rear and front portion are about the same size and capacity. On the OBS the rear brakes have that small portion cause it doesn't use alot of brake fluid as the shoes wear. Since you swapped to discs as the pads wear it could suck the small portion dry of fluid. Plus the NBS unit is built for a truck with 4 wheel disc brakes.

You already have stainless brake hoses installed?

 

[StabbinStevem]

Yes, all of the lines are stainless or hardlines. I may try a NBS master cylinder once I get the adapters Needed for the different size port on the NBS M/C.

 

[SuperStepside]

Let me know the adpater size since I'd like to swap over to NBS unit too.

 

[StabbinStevem]

It needs to be a 9/16-18 female inverted flare to 1/2-20 male inverted flare... But I cannot find that exact fitting for sale anywhere, so I may just buy a 1/2-20 inverted flare to -3 fitting and run -3 stainless hose to the first brake fitting on my proportioning valve and use a 1/8NPT to -3 fitting on that.

 

[SuperStepside]

It needs to be a 9/16-18 female inverted flare to 1/2-20 male inverted flare... But I cannot find that exact fitting for sale anywhere, so I may just buy a 1/2-20 inverted flare to -3 fitting and run -3 stainless hose to the first brake fitting on my proportioning valve and use a 1/8NPT to -3 fitting on that.

I know my napa has a full assortment of fittings. Gonna go there.