I have my dash out trying to get the gauges to function. My performance gauge used to work fine two years ago and last year it started to work very slowly. This year it worked even slower, so now that the dash is out I'm trying to fix it. I removed the nipple and there was some corrosion inside the nut. What has got me totally confused is what was under the vacuum fitting. There's a staked screw under it with no hole in anywhere in sight. Ok, I give, how the hell is this supposed to pull a vacuum through it?