Mallory 4309 return regulator

Yes human vacuum pump. My mityvac died. Put a hose on it. Won't hold vacuum. Pulled the line off the forward filter. Fuel pumpin out like a garden hose. Fills a 5 gallon pail quickly. Maybe I'll try it when the gage reads 3 lbs. Doesn't take long.im beginning to suspect the feel line is collapsing inside.. This is about 15 year old aeromotive 8an hose. They told me yesterday that the hose really only has a service life of 8 years. The ethanol could have softened up the rubber and the pump is sucking it closed. I am going to change the feed line to the pump just in case.
I agree if the diaphragm is blown how come no fuel leaking out? But again it doesn't hold vac/boost. So I believe it's bad. 25 bucks shipped from Holley on its way.