200A and 202 reproduction
frames back
in stock.
offrink
I have a 427 external pump that pumps well but the check valve leaks. I disassembled and cleaned well. It still leaks even with the air stem tight. I honed the point of the air stem to clean it up as there was a ridge. I read previous posts how the screw for the bb was to short or the bb went deeper and a spacer had to be used. Well I did that too and it was either so tight I couldn’t pump it up at all or air leaked. I’m got about 5 hours into just the pump on this lantern. It runs great when it has the pressure! Other than the bb is to small, I’m out of ideas. Any suggestions? 
Ben
Coleman 275 Appreciation Syndicate Member #0035
Looking for B-Day dates of 6/80, 2/84, 3/11, and 12/13
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Gunhippie
The CV on the "external" pump 427 isn't where you think it is. It's on the side of the pump tube and can only be accessed by removing the pump.

It's on top of the pump tube, far left, under the little hex screw:

[28433385194_00d8df7d7f_b]

The actual CV is a tiny ball bearing and super easy to lose. The extended impact socket is for removing the pump, and is best used with an impact wrench (rattle gun). It's almost impossible to do this without damaging the hex nut of the pump tube--as you can see.

Try pumping carb cleaner through the pump first. Remove the plunger, fill the tube up about halfway, let sit for a few, then pump through. Repeat until tired of it.

And remember that the CV is never a 100% seal. It just holds the pressure back enough to pump it up, then the airstem seals the pump off.
It's priceless until someone puts a price on it.
Walk a mile in a man's shoes before you criticize him--then you're a mile away, and he has no shoes.
Texan's last words: "Y'all--hold my beer--I wanta' try sumptin'."
Timm--Middle of nowhere, near the end of the road, Oregon.
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TucsonVwColemanCamper
Use the search and type in “427 air stem and seat leak” . I’ve had this problem and a few ideas were given , I don’t know how to copy an old post . But was able to find it using the search. Good luck .
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offrink
The pump has been taken out already and so has the bb. Disassembled and cleaned using carb cleaner, lye based detergent, and vinegar the pump tube, bb, and screw/hex. I tried all the suggestions I could find. 
Ben
Coleman 275 Appreciation Syndicate Member #0035
Looking for B-Day dates of 6/80, 2/84, 3/11, and 12/13
Quote
TucsonVwColemanCamper
Someone suggested using a little solder on the tip of the air stem , to create a soft lead coating to make the seal . I was able to use a pencil shaved down with a small flat tip with a small piece of sand paper glue to it to get past the threads in the bottom of the pump tube that the air stem threads into and touch up the seat area . 
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offrink
Good idea to touch up the seat area. 
Ben
Coleman 275 Appreciation Syndicate Member #0035
Looking for B-Day dates of 6/80, 2/84, 3/11, and 12/13
Quote
Gunhippie
Sorry--didn't read the original post closely enough.
It's priceless until someone puts a price on it.
Walk a mile in a man's shoes before you criticize him--then you're a mile away, and he has no shoes.
Texan's last words: "Y'all--hold my beer--I wanta' try sumptin'."
Timm--Middle of nowhere, near the end of the road, Oregon.
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offrink
Any other ideas?it is definitely coming out of the ole in the bottom of the pump tube. 
Ben
Coleman 275 Appreciation Syndicate Member #0035
Looking for B-Day dates of 6/80, 2/84, 3/11, and 12/13
Quote
Gunhippie
It's always possible that the leak is a solder failure around the seat of the air stem. You need to put some alcohol or something similar--carb cleaner, acetone--in the pump tube, with pressure in it and the air stem closed, then look closely to see where the bubbles are coming from. If it's from the edge of the seat, you'll need to do some soldering.
It's priceless until someone puts a price on it.
Walk a mile in a man's shoes before you criticize him--then you're a mile away, and he has no shoes.
Texan's last words: "Y'all--hold my beer--I wanta' try sumptin'."
Timm--Middle of nowhere, near the end of the road, Oregon.
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SteveRetherford
file a little length off the screw ?
[DrSteve2]    Steve , Keeper of the Light !!!
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offrink
I pressurized the fount slightly and took out the air stem and put some carb cleaner in it. Lots of bubbles in one spot. Opened up the fuel cap to let more pressure out until it barely bubbles. It comes up where the air stem threads are. Even if the air stem screw it a little long, the check valve shouldn’t be leaking so bad. A little, I understand, until I close the stem but it’s not even close to sealing. 75 pumps and it’s out of pressure, with the stem closed, in 2-3 minutes max. 
Ben
Coleman 275 Appreciation Syndicate Member #0035
Looking for B-Day dates of 6/80, 2/84, 3/11, and 12/13
Quote
SteveRetherford
try a different air stem , ill bet your honing didnt help . it needs to be perfectly conical . i have also put in new BB's in the past . often these air stems are rusty steel shafts . i like to swap em for a brass one .
[DrSteve2]    Steve , Keeper of the Light !!!
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Gunhippie
The air stem from most any suitcase stove pump will fit. Might need to be cut down a little, even. I think I have a 426 stem in one of mine.
It's priceless until someone puts a price on it.
Walk a mile in a man's shoes before you criticize him--then you're a mile away, and he has no shoes.
Texan's last words: "Y'all--hold my beer--I wanta' try sumptin'."
Timm--Middle of nowhere, near the end of the road, Oregon.
Quote
offrink
Good info. I’ll try swapping them out. Anyone have an idea where to buy a new bb that definitely is the correct size?
Ben
Coleman 275 Appreciation Syndicate Member #0035
Looking for B-Day dates of 6/80, 2/84, 3/11, and 12/13
Quote
mnhogrider
I suppose as a last resort you could tap the hole in the pump cap to 1/8 pipe and put one of these schrader valve fittings in. Then put an O ring under the cap to make it air tight.
It wouldn’t be original but I think it would work Click image for larger version - Name: 8D3ACE86-21C9-4802-A08C-8D27605ADABE.jpeg, Views: 27, Size: 125.60 KB Click image for larger version - Name: ABFF5BCD-B68E-49F6-9BD9-6E1B9D5BBCF5.jpeg, Views: 28, Size: 119.50 KB
Steve
ICCC Member #1396 
BernzOmatic Appreciation Club #017
Mack, Cat and Cadillac.
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