I installed a summitt vacuum can resev on my Cuda 340 - I plumbed it as follows, from intake to check valve on can, brass fitting on can to checkvalve on power brake booster. For some reason it is not working ! The brakes are rock hard, If i disconnect the can and go direct to the brake booster the brakes work, I added the can since i have approx 12-13 hg at idle !

Do I need to remove one of the check valves ?