soft pedal

[Bullitt-]

Will holding this valve open primarily help the rear brakes or will this also help get air out of the front lines too?

I was theorizing that this tool isn't necessary for the "pedal bleed" method as I have always done that and never had an issue. Upon further review of my service manual this does seem to be the case. It states the following

(3) Pressure Bleed. This method of bleeding is influenced by the metering valve, Bleed pressure which is normally about 35 psi is high enough to cause the metering valve to close, stopping the flow of fluid to the front brakes. However the valve can be held open manually by using Tool C-4121 to pull the valve stem out.
Caution: Under no condition should a rigid clamp, wedge or block be used to depress the valve stem , as this can cause an internal failure in the valve. resulting in complete loss of front brakes.
It should be noted that the pressure release valve stem is in it's innermost position when there is no pressure present. No attempt should be made to further depress the valve stem.
 

[GoMangoBoys]

We re-bled the brakes using the old press the pedal method.  It is better, the light went off, but I still can't lock them up.  When we did the pedal method bleed, we did it with the engine off, so no power assist.  I seem to recall having issues once before with doing that.  I may try it again with the engine running.  I may also try to run a higher volume of fluid thru the system while bleeding each wheel just to make sure that there isn't a bubble close to the MC.  I usually don't have this much difficulty.

[bc3j]

I have a Motive pressure bleeder and tool c-4121. My pedal is solid. I over do the bleeding, but the brake fluid is cheap.