Re fuel caps, my 53 model C180 has recessed wells with raised filler necks and screw-on vented caps. There is a convex flip-up cover over the whole works to keep out if not the rain itself, at least large hailstones. I've seen several other 180's with the same arrangement, including a buddy's 54 and another buddy's 56. However, another buddy with a 54 has flat covers (not flush caps!) on his which he claims were standard issue for (at least) the 53 & 54 model, and that the convex covers came out later. I can't see why Cessna would go from a nice (aerodynamically) clean flat cover to a dirty convex cover, so I'm thinking he's wrong and that the flat covers are an aftermarket item. I checked the changes-by-model-year article off Stancil's old website and no mention of fuel caps / covers until 1960 : "flush fuel tank caps ..... to replace the original countersunk caps".

I posted about this on the 180/185 Club site, but only got one response which didn't really address my question. Anyone here have any info on this? And no offense but please stick to the point-- the whole "killer caps" vs Monarch caps thing has already been discussed elsewhere.

You have originals like my 54 came with. Best thing you can do is install Monarchs. Your buddy might think his were an original option but they weren't. Also, if you install Monarchs, it brings the top center of the bladder up a little and you might actually get a little more fuel in there.

Yes there were flat covers. My 57 182 has them. There must have been a shorter cap because someone took a hammer to them to give clearance for new style caps. They have some spot welded structure on the back so they are not homemade.

Went and drove around merrill and looked at 20 or so old model 182 and 180's. Found one other 57 182 with the flush covers.



Maybe it was a 57 182 only thing and your buddy has some 182 covers??

The rest were like the ones you are talkin bout.

Hotrod, you see the circle of many screws down in the bottom of the sump around the cap. Imagine bringing that up and inch or maybe a little more----do you think the interior of the bladder got a little bigger?

PAMR, thanks for doing that research. Looks to me like the neck is shorter for the flush covers than for the dished covers. And thanks for staying on point.

hotrod180 wrote:....And no offense but please stick to the point-- the whole "killer caps" vs Monarch caps thing has already been discussed elsewhere.

Yes Marty, I agree that the top of the bladder will be higher (and the tanks a little larger) with Monarch caps installed. I know about Monarch caps, in fact I have a set that I haven't installed yet. But that's not what I was asking about....

180Marty wrote:You have originals like my 54 came with. Best thing you can do is install Monarchs. Your buddy might think his were an original option but they weren't. Also, if you install Monarchs, it brings the top center of the bladder up a little and you might actually get a little more fuel in there.

Keep your head up with monarch caps. I fly with 3-4 people around here where monarchs are made and they've removed theirs. Is some cases, the rubber o ring in them becomes compressed and if that happens, fuel can siphon out of the tank during flight. During a 2 hour flight, my friend was telling me a story on how this happened to him previously and low and behold it was happening during our flight. We were in a rugged treed area and couldn't land and when we did, we had 2 gallons left. Monarchs answer was to flip the gasket to the non compressed side and it will work fine. Pretty hard to do during flight. the guys that sells them carries around a huge bag of them while at Oshkosh and sells them / gives them away. Kinda tells you something. It's happened 3-4 times that I've heard about. That's 3-4 times too many for me. Be careful.

Checked my 1953-62 C180/182 IPC yesterday. I found only one "door assembly, fuel"isted- p/n 0721300-16. Maybe Cessna made both flat & dished covers but assigned the same p/n to both? Seems possible but unlikely.

The IPC also showed the overflow drain assembly, applicable to C180 s/n 30000 > 50448 a well as C182 s/n 33000 > 51825. Seems like my 53 should have one, but it doesn't so who knows.

My parts manual shows just one number listed and pretty sure the humped up version is correct. My very original 54 does not have a drain tube either.