ATF level in reservoir

[Montreal]

I have a brake issue. City driving braking OK. On highway, emergency braking ,I have to push very hard ( slight/medium resistance also felt on the brake pedal) but not enough braking force, so braking distance too long. All fluids changed, all pads changed, all bleeded...
Is it normal the ATF level does NOT come down when I start the engine ? It remains at 1 cm below reservoir's rim which is the level obtained after pressing the brake pedal 20 times when engine stopped.It never moves from this level, engine on or off...Is it possible the bomb is toasted so it is filled with ATF ? This would explain the ATF in the container has no free space in the bomb to fill it ?

Brake bomb ? MC? Brake servo ? Pump ?

[Mike W.]

Typically failure mode for the accumulator, AKA bomb, is normal driving it feels just fine. Putting from stop light to stop light, good power brakes, just like you would expect. But if something happens suddenly and you have to jab on the brakes it feels like there is a brick under the brake pedal. You do have brakes, but no power assist. Slow down a little and ease up on the pedal and it feels fine again. You can test it at 20MPH, just hit the brakes hard and see what happens.

Another test is after being run and you shut it off, you should feel like you have power brakes, for a while. With a new accumulator the pedal will feel like it has power assist for perhaps 15 pumps of the pedal. A bad accumulator will be rock hard on the first pump.

Your description of the fluid level makes sense for a bad accumulator, but I've never tested it that way.

[Montreal]

I will start with the bomb..Will be back when installed for follow-up...