I have been working on my Egret 350 which I bought in Egypt and I have a problem with the pump. When I push the handle in after it has been standing, I hear air going into the tank, so the NRV is working, but when I pull the handle out, I t does not allow air into the pump tube and, if I release the handle, it is sucked back almost to the bottom. The result is that there is no air in the pump to be pumped into the tank. The leather is a Petromax leather, I don't see any difference between this one and the Egret one. Any ideas why it does not let air past it on the upstroke? Jim.
You need to give us a picture of the pump so we know which kind you got. Just the pump rod with its head. Does it have the "floating head"? I mean, does it have the kind of pump where the part with the leather has a bit of slack, and a tapered seat against the pump rod. Sometimes people who hasn't understood the function has screwed the things tightly together, which means that the pump head doesn't leave the tapered seat on the pull. But on the other hand, some cheaper lanterns only has a fixed cup, which rely on the air to just simply pass by the leathers outside on the backstroke. It works too, but might give a more "spongy" feeling.
It is a loosely fitting leather cup, Christer but I think I've done the nut up tight, so this might be my problem. If I didn'd do it up fairly tight, the nut and leather cup fall off and sit stuck in the bottom of the tube I'll try to get some macro pics of it. Jim.
The pump on my Egret has a floating leather cup and a hex retaining nut with three small holes. The stop plate behind the leather cup is slightly concave. It works just fine.
Same as mine, Phil. Is your leather cup free to move about? I don't know why it seals in both directions, the leather cup is on the right way round. Jim.
Mine floats freely, with a mm or two of play between the nut and plate. How big is the hole in your leather seal? Is there a passage for air to pass through on the back stroke?
I'm not sure, Phil, I'll have look tomorrow. I never thought that the air might come through the centre hole, I'll measure it tomorrow and let yo know, If it's a tight fit on the shaft, I might try cutting it a bit larger! Thanks, Phil! Jim.
You could also file away a segment of the rod to help the air pass on the back stroke. That's what they did on some early stoves. But that was before the tapered seat was introduced. These early ones sealed at the push by instead seating the loose head against a flat washer (with a flat piece of leather also on the backside of the cup):
Hi, Christer, Mine is not like that. The rod is completely round and there is not the central insert in the leather, there is just a nut which is round with two flat sides, the same as my Petromax.¨ Jim.
Jim, I know yours not look like this one. I think I have a good idea of which kind you got, even if you still refuse to post us a picture of it... You said: "...If it's a tight fit on the shaft, I might try cutting it a bit larger!" To that I replied that you always could file away a section of the rod if you think it wasn't enough space to let the air pass freely when pulling the pump out. Just like they did on the eartliest pumps. My picture of the stove pump was only to illustrate how it looks when a segment is removed from the rod.
Christer, I have not refused to post pictures of my pump, I have simply been too busy to take any. I enlarged the hole in the Leather and that cured the problem, I also extended the thread on the shaft, which allowed me to add a locking nut, to prevent it unscrewing and being stuck at the bottom of the tube. I really have appreciated the help I received on the CCP, Thank you all very much! Jim.
