Have you checked the vacuum shutoff valve (white cap with brown hose)? If you played with the alda you probably scatched the valve enough to leak. It happened to me, and I had to go to desperate measures, but it still works to this day!

I used a clean DW-40 little red straw where the center of the white cap is, and stuck it down in the hole a little ways then connected the vacuum hose back. Has worked ever since.