Well, I needed to be in town for a wedding this weekend, so I did something a little different though still related to backpacking. After the drive to the Venable Lakes trailhead, last month, I noticed a fuel smell coming from my pack. I figured I bumped the on/off valve on my Coleman 400A backpacking stove and some fuel had leaked out. When I got home, I pumped up the stove and noticed that there was a slight hissing sound. I tried to tighten the packing nut, but it didn’t stop. I’ve owned this stove since I bought it new in 1987 when my wife and I went on our first backpacking trip in the San Jacinto wilderness. Anyway, I figured it was probably old and worn out so I ordered a new one from Coleman.
The new valve arrived last Friday, just in time for my at-home weekend. Perfect.
Disclaimer: I am only showing what I did to repair my stove. Stoves can be in all states of disrepair (rust, etc.) and some skills and tools may not apply to everyone and fuel leaks can be dangerous! If you try this on your stove I wish you the best, but I will not be responsible for damage to yourself or your stove. Proceed at your own risk.
I disassembled the stove by removing the generator bracket with a Philips screwdriver, then generator. The nut on the generator requires a 7/16″ open-end wrench. Then, I removed the burner ring set and the burner bowl, followed by the burner box assembly. All of these only require a Philips screwdriver. If you’d like a diagram, I have scanned my original owner’s manual and can send it to you. The diagram of the stove itself is also available at coleman.com (Edited 11/9/2015, This is now difficult to find at Coleman). The last and most difficult part of the dis-assembly was removing the 400B5571 valve assembly. This is the valve with the red lever. It was a bit unnerving as it was so tight I needed a an extension pipe on the 1/2″ wrench to get enough leverage (hence my disclaimer). I thought for sure I was going to break the fitting on the tank (Coleman calls this the fount). Eventually it came loose and I removed it.
First thing I noticed was that the new valve was not identical to the old one. Coleman’s website shows that the original is no longer available and provides the new part number.
I test fit the new valve assembly and found that after it got snug it needed 3/4 of a turn with the 1/2″ wrench (I did not use the pipe extension here). I backed out the valve until there was only one turn left (I counted 7 turns in to tighten it) in the fount. I applied some Loctite Blue, 242 Threadlocker to the threads all the way around and then threaded the valve back in until it was quite tight (7 total turns).
Before total reassembly, I checked that the flange on the generator matched up well to the new valve assembly. I also made sure I opened the valve, which retracts that little stem (not on original valve). It didn’t look quite right at first so, I installed and tightened the nut and then made sure the Low/High valve fit properly in the opening where it enters the burner box. Then I disassembled it again. I tried this several times as you don’t really want a gas leak here (another reason for a disclaimer).
Before the Loctite began to set, I installed the burner box to make sure the valve does not interfere or touch the burner box assembly. If it does, adjust the valve position with the 1/2″ wrench to have some clearance. Then, I installed the burner box, burner bowl and burner ring set. Finally, I got the generator in position and tightened the flange nut at the new valve and then put the Low\High valve in the proper position and installed the generator bracket.
I tested the stove for leaks . . . first, by pressurizing it and listening for leaks, and then by actually lighting it up according to the instructions. Haven’t found any leaks so far. Overall, the valve replacement went smoothly.
The Curious Valve
I was curious about this valve assembly.
I removed the gray plastic pipe from the brass valve and noticed that the valve isn’t really an On/Off valve at all. Air goes right through it in any position of the red lever and I know it wasn’t this bad before, otherwise I would have had fuel everywhere. It appears to only regulate the gas flow. The actual on/off valve, which is actuated by a little nut inside the red-lever valve, appears to be a car-type valve-stem valve which resides in the gray plastic tube. Interesting.
Since the brass valve doesn’t actually shut off the gas (at least not on this model stove), I wonder if the ACTUAL problem was this inexpensive tire valve. I cleaned up the assembly and saved it for possible future use. Since the time I fixed this stove, I discovered that this little valve is available from Coleman Parts dealers.
Maybe it’ll be good for another 26 years!
Edited November 11th, 2015 to add the parts list and instruction sheet from the 400A manual.
Here is the instruction sheet:
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