power brakes not working

[chargerdon]

I installed a brake booster onto my 66 Charger that has front discs.   Not getting any power.   What is the minimum vacuum to operate power brakes ?   I read 14 bars at idle and it goes as high as 22 under throttle taking the vacuum from the vacuum port on the back of my 1406 Edelbrock carb.  .   

The brakes do operate but without any noticeable power assisst...   Feel the same with the vacuum hose disconnected as it does connected.   

I think the booster is defective.. thoughts ?

[Cuda Cody]

Was it a new or used booster you put in?

[RUNCHARGER]

What type of booster? I briefly sold parts a a Hot Rod shop and the boss did not carry the smaller boosters as they were ineffective.

[70vert]

I had no luck with an electric booster, it was a Summit brand. Like you said, no real improvement. I ended up going with hydro-boost, which is an amazing difference.

[chargerdon]

Was it a new or used booster you put in?

New booster... the car has SSBC front discs and so i bought the booster kit from SSBC.   Their tech suppport is very friendly and insisting that you need 20" of vacuum.   I have about 14" at idle and it rises to around 22-24 when i blip the throttle in park.   I think 14 should be plenty to at least give some boost. 

[bdschnei]

Make sure the check valve between the booster and the vacuum source is operating correctly.

A quick test to check the booster is to pump the brakes a few times with the engine off. Then with your foot applying slight pressure to the brake pedal, start the car. The brake pedal should be slowly sucked to the floor in a couple of seconds as vacuum builds in the booster.

[chargerdon]

I did this test... First i removed the check valve and can suck thru from the hose end but cannot blow into it.   I believe this is the proper check valve action.  Then reinstalled the check valve and removed vacuum host at the carb and then sucked the end of the hose...clean sucking till i filled my lungs and never stopped...no back vacuum.   



Is this a solid indication that the booster tank is defective?   



I tried the same thing on wifes town and country mini van and sucking on end of hose it immediately gave stoppage and had vacuum back against my tongue as a comparison. 

[chargerdon]

Mystery over.   Took tank back off and examined.   No Grommet on the rod to the master Cylinder.

[chargerdon]

SSBC sent me a replacement booster under warranty and i installed it today. 

It works great not too sensitive yet stops well, i still have some finish work to do..  i.e bleed the brakes as it isnt a full firm pedal yet, reinstall a clip that holds dash wiring harness which was in the way of getting a ratchet to the top right bolt for the booster tank.  Etc..