Booster for 61 Caddy with disc brakes

So I've had this Cadillac for a while now and it's time to tackle the brakes. The gentleman that had it before me had already converted the front to disc brakes. Trouble is, the pedal is harder than a.... well, it's really stiff. Not sure why but it seems to me that the booster he has on it is too small for starters. Anyone know what size should be on this type of car? Any other suggestions/solutions are also greatly appreciated.

mayday

 

What you describe is the symptom of a bad booster, not one that is too small.

 

Are you sure its getting vac***? Do you hear any hissing like a leak? If it has a check valve, maybe its not working or turned around backwards (some makes are inline and its possible. seen it/done it myself)

 

We checked the vacuum yesterday and it was getting about 20. If I remember correctly he said that he picked the booster/cylinder up on eBay so who knows what the story is with that. So, new booster and master cylinder or just booster? Or jsut rebuild? And does the size matter at all if I were to get a new one?

thanks for your help guys.

mayday

 

But there is a "hiss" when I step on the pedal though. My old man and his crazy neighbor seemed to think that wasn't the issue though.