Mushroom cap

[TheLimeRanger]

So I found a mushroom cap for the flex tube coming off of the charcoal canister. How does it stay on the plastic sleeve? It can’t just sit on top. One bump and this thing is gone. Is there an o-ring that’s supposed to go in there or something. ? Thx

 

[71broncman]

The caps are held in by friction between the tube and the ribs inside the cap. I'm pretty sure the flex tube doesn't get a cap on it. If I remember correctly, the flex tube pushes into a fitting on the stock air filter assembly. I never had the stock air cleaner, but I think I recall how they were plumbed from back in the 70's.
Mark.

 

[NGABronco]

Me thinks the flex tube is ribbed metal and the mushroom fits down into it with the ribs on it???%)%)

 

[jckkys]

If I remember correctly, the '74s have a charcoal can on the frame with two 1" nipples. One gets the mushroom cap.the other gets the 1" corrugated aluminum tube from the air cleaner. The mushroom cap kind of snaps into nipple on the canister. Mine never fell off. Are you sure you're putting it in the correct nipple?

 

[TheLimeRanger]

So mine has 2 flex hoses from the canister. One goes to the air cleaner and the other one just vents. The one that just vents has a sleeve in it that I thought was missing the cap,so I bought one on eBay. Here’s a pic of what I thought it was supposed to look like based on another bronco

 

[NGABronco]

Hey LimeRanger, man I had to dig deep to find this junk!!! I think the original hose had a fabric coating or cover, but a metal core. I found this at Advance Auto many years ago, not sure they carry Gates anymore, but thats a start. Good luck!!!;D;D;D

 

[DirtDonk]

The early ones were just sleeves to hold the hose open. No cap, which made it look incomplete.
At least all the ones I saw were. Perhaps they had already lost their caps!

The later plastic canisters did get a cap directly on to the canister's fitting, but the early ones with the hose could have had either a sleeve, or if I remember, later ones (like '73-'75 maybe?) had caps.

Paul

 

[TheLimeRanger]

So I guess the question is, am I missing the cap or not lol. I have a 1974. With the exception of the rims and the seats it’s all original. It looks incomplete without something on it but there doesn’t seem to be a way to attach the cap to it. The cap fits on the sleeve but a slight breeze would knock it right off. Anyone here have a ‘74 that can check theirs?

 

[DirtDonk]

Have you tried slipping the cap directly into the hose, without the sleeve?
Alternately, I wonder if there is a different type of cap? Seems that the one you have is designed (at least it looks that way from here) to be slipped into the plastic fitting of the canister directly, or perhaps into a different design sleeve.

At least try it on the canister (if you have not already) to see if it's appropriately sized for that fitting.
That would be cleared up if someone has a '74, like you said. Hoping someone does, because I'm very curious now.

In the meantime, if you were driving it and still waiting for an answer, you could just put the cap directly on the canister and drive it that way. It would still function at least enough to drive it, as long as it stays in place.

Paul

 

[71broncman]

Someone added the flex tube to the nipple in the center of the canister. The cap was pushed into the nipple in the center of the canister (look at NGA's pic). Maybe a PO did it to keep water out of the canister when fording streams, but who knows. The tube going to the air cleaner is correct. Simply put, the center nipple is really just a breather and the cap on it is to keep crud out and still be able to breath. Hope this answers your questions.
Mark.

 

[DirtDonk]

Nope, factory.
While I have seen some popped directly on to the canister, those were mostly passenger cars. Can't remember the last time I saw a truck with the cap on the canister.
As you say, the higher location is good at least for debris and water resistance. Might even be some "chimney effect" thing going on, but more likely it's just water.
Being down on the frame like that, water would get in very easily in the off-roading world they were intended for.

Maybe it's a first year '70 thing without the hose? My '71 had the hose, and every other one I can remember had it too.
When they changed to the plastic high-mount canister on the firewall, the cap was put directly on the port.

Paul