I recently installed a new power disc brake conversion kit on my 70 charger (MBM Brakes) but brake performance was very poor. I was thinking about modifying the brake linkage or get a smaller master cylinder (currently 1"). But yesterday I realized that I might have done something wrong when I hooked up the booster. My old booster had a check valve with two outlets - one for the vacuum line from the manifild and one for the vacuum canister for the dash controls (which is located in front of the radiator support). The new one just had one outlet for the manifold vacuum line - so I just put a T piece in the line to split off the vacuum for the canister.
Could it be that now the canister "robs" the vacuum so that the booster is undersupplied? How does the old check valve work in regard to providing vacuum to the canister - I guess it doesn't simply T off inside the check valve.
Unfortunately I already pulled the brake booster so I can't check what happens if I just hook up the manifold line...
