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I have a very clean 1987 F-250 with the 460. I have also posted this in the Bullnose section since 87 was the last year of the carbureted version. It was my grandfather's that I am trying to keep on the road. Now I reached a year when I wasn't supposed to have emissions on the truck anymore, but they changed the law the next year, so I need to keep the thermactor system going. I was eventually able to get it to pass emissions, so I am good on the tags for a year. Yet it was a bit of a pain. Well, I think I also found reasons why it was hard to tune the carburetor correctly. While I was taking the entire front assembly off, many of the black vacuum hoses were old and cracked; I can replace those, but one of the green, harder-plastic vacuum lines seems to have been cut by someone. The very reason I don't like anyone else working on this old of a truck. Does anyone have a source for these kinds of lines? If not, does anyone have any suggestions for a different type of line that would work? My second question is about the large silver up pipe coming from the passenger-side exhaust manifold. What is it for? It seems like it should be connected to the bottom of the inlet to the air cleaner, as I have seen a hose for sale for that position. Yet that round piece on the air cleaner, where a soft pipe should go, doesn't actually go through into the air cleaner inlet. I also suspect this is why I smell more exhaust than I used to in the last few years.
I bought 20 feet of 5/32 silicone hose on Amazon, Evil Energy brand and a box of assorted vacuum Tee. It will replace 90%. I don’t know the silver hose!
If not, does anyone have any suggestions for a different type of line that would work? My second question is about the large silver up pipe coming from the passenger-side exhaust manifold. What is it for? It seems like it should be connected to the bottom of the inlet to the air cleaner, as I have seen a hose for sale for that position. Yet that round piece on the air cleaner, where a soft pipe should go, doesn't actually go through into the air cleaner inlet. I also suspect this is why I smell more exhaust than I used to in the last few years.
Find a rubber vacuum hose from the local parts store that is the same inside diameter or buy some silicone hose.
That is a shield over the exhaust manifold. A hose connects that to the bottom of the air cleaner snorkel to funnel warm air to preheat the intake air for cold climates.
Your local parts store should have this hose in the “help” section. It should look like this…
There is a flapper in the snorkel that closes depending on temperature.
You should not smell exhaust. There is a leak.
Last edited by My4Fordtrucks; May 25, 2026 at 06:07 PM.
