[cadillac_al]

I have never had to do it but some people put a gauge on their brake line to test brake line pressure. It sounds like it isn't getting enough brake line pressure but I would have no idea why.

I never liked hydraboost in the past but I have it on my 86 motorhome and it seems to work quite well. I would think a K30 would use the same master cylinder as a P30. If not I would try something out of left field like try a master cylinder from an 86 P30. Good luck