Brake booster vacuum routing help needed

[adidas_kn]

Looks like I was missing some parts causing insufficient pressure at the brake booster. I installed a new booster check valve on the booster, verified the vacuum reservoir still holds vacuum there are no leaks in any of the lines. I went to the Ford parts counter and the Internet to get an idea of what I'm missing. I was told I needed this vacuum y called an Aspirator brake booster to connect both the reservoir and booster to the B/B port on the manifold. I checked and this aspirator doesn't hold any vacuum like a check valve. Do I need another 3/8" check valve to keep as much vacuum in tree brake booster circuit as possible? Can anybody look at their gen 2 sho mtx and tell me how this is setup and if I'm missing anything? I have a Taurus vacuum diagram pictured and a ford exploded parts view. They both show something different. My understanding is that the B/B outlet on the vacuum manifold feeds a check valve with the respirator which splits to the resevoir and booster it also boosts vacuum to the booster which has a brand new working check valve. Any pix of the routing would be fantastic. In the pic of the Aspirator Brake booster y #2C318 I need to know which tube goes where as in booster #1, Resevoir #2, Manifold #3.

 

[Slo-Sho]

The brake booster check valve (part num 2373 in the 1st diag) should only hold vacuum in the booster, the rest of the lines are atmospheric when the engine is off. Does the booster hold enough vacuum for 1 pedal application after the engine is off? I'm rather unclear what the exact issue is??

 

[adidas_kn]

My issue is that I have good strong brakes at low to mid RPM but they get harder due to decreasing vacuum at higher RPM's. Yes the pedal get one good pump when the car is off.
The expensive Aspirator Booster listed by ford actually seems to reduce vacuum when hooked up. I can't find a propper vacuum diagram for this car. It's my understanding that the Resevoir and booster are supposed to be on their own check valved circuit to provide the reserve to the booster at higher RPM's. I have deleted the cruise control system so that is plugged off on the S/C port on the vacuum manifold.

I will try to remove this aspirator from the circuit and try the booster straight to the BB port on the vacuum manifold. I will also try to put one of the 3/8" check valves with a T splitting to the Resevoir and booster.

 

[Slo-Sho]

Yeah run the booster directly to vacuum and see if that cures it. When you are off the gas at high rpms, that is when the motor produces the most vacuum. Also, what conditions if I may ask are you on the brake pedal at high rpms?

 

[adidas_kn]

Revving the car our in 1st or 2nd gear then emergency breaking.

I fixed the issue. I installed a 3/8" check valve at the BB port on the vacuum manifold then hooked up a 5/16th T and then hooked up the resevoir and booster to the 2 legs of the T. Stops like a boss now. It wants to lock the brakes up and slide at almost any speed if you out your foot into the brakes. It stops jsut fine now. These 13" Cobra front and 11.6" rear brakes are damn good.

The real culpirt for all of this was that the rubber seal that goes between the master cylinder and brake booster was dry cracked and leaked. I replaced that and put this new vacuum circuit in and now all is well.