That lockout tool is a great item to help keep the shuttle valve and dash light working properly. Which was always a pain with the old H-block and original prop valves (though not as big an issue with the prop valve).
That rod under the boot is the same pin with the same basic function as the original.
Some you need to push, but I thought all the aftermarket ones I've seen needed to be pulled.
The way to tell unfortunately usually requires a helper. Have someone push hard on the brake pedal while you watch that pin. If it pushes out with the brakes applied, grab it with something gently to keep it pulled. You could still use some needle-nose locking pliers, but it looks like there is still a groove you could slide a clip over to hold it in place. Maybe that would work too.
I wonder if anyone still sells the special clippy-doodle-thingy that they used to use just for that?
Anyway, many people have been able to get their bleeding done without holding out on the valve, but I would think it's still a best practice to hold that valve in the open position anyway.
The difference is likely how far open you hold the bleeder valve at the wheels, and how hard the helper pushes on the pedal. Fluid is going to pass the delay valve under pressure, but if the bleeding pressure is very light, there might not be much force at the wheel.
I like the concept of the delay valve, but still prefer to update a system to a manually adjustable valve in the rear system only. It's just simpler, and can be fine-tuned better for today's Broncos that are very likely balanced completely differently from when new.
Paul
