Does anyone have info on ac9803 dual action fuel pump vacuum line installation? Can't find any information. There are two threaded ports and one port with no threads on the vacuum portion of pump.
I have the vacuum lines that came off a 58 235 with fuel/vac pump. The two threaded ports get the lines that are routed alongside the fuel and distributor vacuum lines around the front of the valve cover. I'm not sure at this point which of the threaded ports is IN and which is OUT, but that wouldn't be hard to figure out by moving the lever with a thumb over one port. My pump is an AC4080 with glass fuel bowl. I don't recall seeing a non-threaded port on the vacuum section, but could go check. If you'd like a photo of my pump, I could do that as well.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Here's a couple of pictures from the 1947-54 Chevy FAM with the diagram of the RPO 340 Fuel & Vacuum Pump instructions. Overall and close up. The pictured pump in this diagram is a slightly different design from your AC 9803, but the number of ports and purposes remain the same.
BTW - The unthreaded hole in the vacuum pump housing is a blind (closed) hole in the casting which isn't used in your application.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
Here's some pics of my AC4080 pump. There's no unthreaded port on it, but there are a couple of small vent holes between the two diaphragms.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
