Can save original pump and obtain a new one. Forgot to mention orings may likely need to be replaced with correct size, even on the pump where it selas to the fuel bottle. Duane
My impression is this: A failure mode has been identified by and described by the user community. That is that the plastic fuel line can degrade over time, and potentially slip past the little drive screws and release the check valve spring, allowing pressurized fuel to escape via the pump chamber. The fix is simple... replace the fuel line at the first sign of degradation, or earlier. Cascade Designs has undoubtedly identified the same failure, and possibly either identified or hypothesized others. It doesn't make sense for them to repair or even describe in any detail the nature of the failure, and here's one reason why: When I got this stove I had no knowledge of this potential failure. I naively pumped up the tank with the fuel that was still in it (though I did use my eyes, ears, and nose to check for leaks around the top of the bottle) and was pleased when the stove ran as though I had last cooked breakfast on it that morning, even though it had probably been around 25+ years since it was last lit. (My grandfather was 100 when he died in 2022 and I think his last backpacking trip was when he and my brother hiked the entire Long Trail in Vermont in 1995 or so.) When I took the time a few weeks later to unscrew the pump from the bottle and peer inside I saw the decayed fuel line sloshing around in the bottom of the bottle. It had snapped off flush with the end of the pump. The top part of the fuel line crumbled as I removed the brass bead to reuse it in the new fuel line. The next piece of fuel line will fail similarly. (Ignoring my copper tube fix for now.) The next owner, whether they're a grandkid of mine or someone who scores some cool old camping gear at an estate sale, probably won't know the critical nature of that little plastic hose. Cascade Designs (understandably) wants nothing to do with that, and even if the rest of the pump is rock-solid it's not worth their time to come up with a fix for the old pump because the new pump is backwards compatible and that is the fix. My copper tube fix was my (first) try at something more permanent. @OMC you make a very good point. The copper tube that I used was from an old air compressor, so it's actually pretty thick-walled and would definitely pass along any shock to the rest of the pump in the event of a drop or impact. That failure would probably be immediately noticed, and not result in a fireball, though it could just crack the pump, resulting in a full break sometime later. Shortening that copper tube would get rid of the extra "leverage" but I have a "version 2" in mind that'll require a trip to the hardware store. More on that later. @Boron40 you bring up some good points that are hard to disagree with. (And very diplomatically I might add.) Like you said it's a matter of risk tolerance and perception of risk. I suppose I'm making the assumption that the soft plastic part (the fuel line) is the only culprit here because that's the problem everyone talks about and I think it's more common to see soft plastic fail than hard plastic. However, the "worst case nightmare scenario" (his words) that was described to me could only be caused by the hard plastic threads failing. My impression was that that was hypothetical, and not something that had actually happened. I know I've read on other threads here about the pump cracking around the valve, but I think that was blamed on people over-tightening the valve resulting in too much strain on that part of the pump. What other failures have been observed with these pumps? @hikerduane might the failing valve threads in your white pump be a sign of deteriorating plastic? How does the rest of the pump look? @Pancholoco1911 It's interesting that my pump has the cotter pins like the right-hand one in your pictures, but my valve wheel has "OFF" with an arrow, like the one on the left in your photos. I guess chronologically mine must fit in between your two.
@bgriffith ill share better pictures later from mine here. My stoves are in a storage unit for now and might be at my storage place tomorrow but is not a warranty to find them in all the stuff is there. Sending a pm
My original style white pump has internal threads that are worn from the valve stem going in and out. If somehow I could come up with a plan I would fix it. I have two even earlier ones that show some cracking, so those are only for a show and tell demo. Duane
I am not familiar with this fuel line failure. Do you mean the air line? Where the air line is attached to the end of the pump? Where the ball, spring, and teflon are? Your tubing crumbled. Mine are broken off. I am sure no one knew that the tubing would not last, or how long it would last. @Doc Mark put together kits to repair the yellow pump years ago.
Hi @bgriffith . I'd like to unwind everthing I said. Which was all pedicated upon your sentence about ejecting from the fuel bottle whil stove is in use. But hearing your further qualification seems to put a whole new spin on this: However, the "worst case nightmare scenario" (his words) that was described to me could only be caused by the hard plastic threads failing. My impression was that that was hypothetical, and not something that had actually happened. I am making the executive decision to trust your judgement. You were there and heard the guy's tone and context and got a much better picture than me. So if you are fine with it so am I. However, I would like to back away even a tad further to stipulate that I have no business being fine with it or not. This is your stove, your life and your judgement!!! You sound like you're a competent guy and you communicated a lot of good knowledgeable stuff about this whole thing so I think your safety is being very well handled by you. You made a sound decision and a lot of other guys here would do likewise. Heck, if I never heard the line about ejecting from the fuel bottle I would go with the pump too!!! However, now I fear I've been scarred for life, similar to being "unable to un-see something" you once saw that was gross or upsetting. I may never trust a plastic pump in these circumstances again! (haha!) Best of luck with your grandfather's stove. That sounds to me like it was an "ace-out" sort of gift!!!
The earliest MSR pumps only had one tube (fuel tube) extending from the pump into the fuel bottle that curves down to pick up fuel from the fuel bottle lying on its side. Later pumps had a second tube (called air tube or air hose) that is meant to prevent fuel from escaping past the check valve at the bottom of the pump in case of valve failure. If there is no tube, or if the open end of the tube is in the fuel, fuel would escape through the pump if there is a check valve failure. The air tube must be curved in the opposite direction of the fuel tube for it to fulfill its purpose. This point is probably discussed somewhere in CCS, but I’m not sure where.
That is an interesting point that I never considered. If the check valve failed. This is complicated when/if the tank is inverted for pressure release IF the check valve is defective.
Yes, that one. I just used "fuel line" to mean the type of hose, rather than the function. That is a very important point which I had not considered. It seems obvious now that you mention it. I had thought about replacing those two little drive screws with a single cotter pin that passes all the way through the pump and hose, but that would allow fuel into the hose, defeating its purpose. I read somewhere on CCS that the little brass bead in the air line is a part of a compression fitting. I think that the other part of the fitting, the little brass tube with a flange on one end, would work better, since the flange cannot pass by the drive screws even if the hose disintegrates. I drilled two little holes so the drive screws can displace the wall of the hose a little bit. I got some new fuel line and slid it over the brass fitting, making sure to orient it so the natural curve from being coiled points up.
So, definitely not applicable in this case, but has anyone had any issues with the metal braided MSR fuel lines breaking down? The old Whisperlite and Firefly fabric over rubber fuel lines certainly had issues, but the more modern ones?
Up until the stove that's the topic of this thread I'd had little experience with MSR stoves. I've definitely seen the equivalent hose on Coleman Apex II stoves start leaking and if I find one that isn't leaking yet I'll assume that it will start leaking any day. Unlike MSR, Coleman doesn't offer any remedy for that, but I've fixed 3 of them using the method discussed on CCS.
