I picked up an unfired Simmerlite for a fair price recently, simply wanting a backup to what I've come to believe is the absolute perfect stove for me (and for that reason obviously unloved by the masses and abandoned by MSR) before availability completely drops through the floor. It came with a fully new pre-Duraseal pump. Lubed and tested and it worked perfected (leather cup needed a reshaping and spindle oring was dry, but fair enough at 18 years unused). Having read some horror stories about the pump being a total dud, from pump tabs to that red ring of death, is there simply no preventing its failure? Has anyone prepped one of these for safer service with reinforcements to the plastic tab with JBWeld? I don't like leaving things unused but I have no desire to turn into a fireball if your collective experiences are to steer clear and pop it onto a display bottle indefinitely! I thought this might be okay as a backup to a modern pump you just toss into your bag unless they're truly unredeemable pumps.
@paultee Fully unused these are great pumps. They have additional features over the older grey/black pumps. But every improvement came at the cost of durability and they all eventually fail. I personally would have great hesitation in using the pump. Keeping as a spare suggests you put it into use when your Duraseal pump is misbehaving. But keeping your least robust pump as the emergency backup is hardly sensible. On the other hand, MSR stuck with this design for 10 years or so. Presumably they can last a few uses. But they are a ticking bomb. I do have a grey/black pump that I use as you suggest. There is one other feature of the Duraseal pumps that I only recently discovered. Older and off-label fuel canisters will use older and newer pumps. But my new Primus fuel cannister has a thread cut which will accept the Duraseal but not the grey/black.
@Scrambler You reminded me that I have a spare parts black and grey body. It accepts the red plunger *a bit loosely of this one. Is it better to just transfer the piston to the black/grey or are those just as faulty as the red version and simply fewer people have called out the black/grey because of the passage of time between pump upgrades? And yes, I'm leaning toward it just being shelved forever, which is a shame, but figured it was worth taking the temperature on these in a fully-new state.
I stripped all the interchangeable parts off my grey/red pump to keep for the older grey/black. All the parts interchange other than the valve. The grey/black has a valve that can be unscrewed entirely while in use. The piston isn't held as securely and the retention ring can slip off the pump. It was fixing these quirks that created the more troublesome faults of the grey/red.
Ah, I didn't realise the "improvements" lead to the future stress points. So if I put these side-by-side: #1: "Improvement" of stronger seating here lead to higher stress cracking point? #2: Does this hold up better than on the newer red/grey or is this a common danger point? #3: was this older lack of a brass nut ultimately another point where the "improvement" created stress cracking?
I think I only have a couple maybe of these, preferring the old yeller and gray/black pumps. The gray/black pumps you have to be careful operating in the dark if the pump plunger/piston comes out because the two halves that hold it in place fall to the ground, especially tough to find then if by a used fire pit with charcoal scattered around. Duane
#1 Yes. They lengthened the slot but the buttressing seems to have removed the ability of the plastic to slightly flex. They all crack here. #2 I don't know. Never seen trouble with either. I can't even recall which of the 2 is supposed to be removable and which is not. The Duraseal itself is great if you swap between bottle brands. It will seal inside, outside, on top- if it could possibly seal it will. #3 The insertion of a brass liner required thinning of the plastic, and simply tightening places lateral stress on the threads. Great on paper, but any movement at all (and that is inevitable) and it will eventually crack. The Duraseal pumps address and fix all these issues, and the additional changes don't create any. The only Duraseal quirk I have met is that the fuel tap can leak under lateral stress. Stop tipping it, it stops leaking.
@pau-i-amor Why not plastic? The critical parts of most old pumps are made of leather, rubber and cork. Hardly the most durable substances. The yellow pumps rarely have trouble, the grey/black pumps have minimal trouble and the current "Duraseal" or "seahorse" pumps have virtually no trouble. The pumps are insanely light- a seahorse pump is 56g, the grey/black 48g. A childproof cap is around 25g. The grey/red pump had serious engineering flaws. Eg the Duraseal/seahorse pump has the brass control screw extension limiter mounted outside the plastic threads. If overtightened it is attempting to compress the plastic. The older red/grey pump attempts to stretch the plastic at the similar location. The plastic can be engineered to resist the compression, but not the stretching. While the plastic pumps can melt, they are actually designed to do so while venting the fuel away from the stoves. They cannot explode. And any suggestion that similarly mounted "metal" pumps are better is eliminated by the fact the pumps are mounted in a plastic threaded collar. So anything that would melt an MSR pump will melt an Optimus or Primus pump. The yellow pumps are all 35 to 45 years old. A solid brass stove of the same age would require at the least replacement of the rubber, leather and cork parts. The grey/black pumps are 25-35 years old. They are nuisances that requiring thinking- but then so do the stoves. The Duraseal pumps are up to 15 years old, and rocking along well. It is the 15-25 year old ones with the poorly engineered "improvements" that give the pumps a bad name. That and poor maintenance. The core elements do not have substantial wear. The pump shafts and plunger handle do not wear. There is no gain in making them from metal. All wearable parts are replaceable, these being the same parts that wear in all pumps.
Thank you for the details on this! Looks like the new grey/red will be a donor to that grey/black and I’ll just stick to using duraseal on all trips. Personally I like the plastic ones (over Primus and Optimus, which double the weight). The weight matters to me as I primarily hike-in and now in the hundreds of firings on those new pumps I don’t have any doubts about their durability/reliability. It does seem like they get flack (rightly in a way) for the sins of the red/grey, but really do perform well.
Dear @paultee, May I ask one thing I'm curious? When you're using the recent Duraseal MSR Red pump in Very cold circumstances, was it worked as its feature well? around below than negative -10degree celsius to -20C? I didn't use in very cold, so would like to know it. afaik MSR offers another one as Artic pump, but I don't know MSR's synthetic pump cup is working or not working well in cold as your avatar photo! Primus Ergo, yes works...
@Yun124 I don't have @paultee 's experience with the icy cold. My understanding is that the standard pump is rated to cope with some cold. The Arctic pump has 2 changes- seals that tolerate cold better, and a leather cup. The leather cup is the same size in the older pumps, and they fit the Duraseal cup attachment. That should be an easy swap for you. I have used one for a time. The seals are said to be fragile at around -20C or lower, though I read that many people just carry spares.
Okay so I'll try to replace the black seal to the leather cup from the gray pumps. I may have 2-3 leather cups from the old pumps and old service kit. up to now the black seal is still working well, but don't know about the tough cold condition. thank you for your advice!
@Yun124 My experience has been good with Msr rubber cup at -10 to -15 Celsius, having never had an issue, but I also don’t carry the pump on the outside of my pack during winter like I do in summer, so if benefits from having some heat from my back. This doesn’t matter if you’re pulling a sled though. I do also carry a spare, but with this black/grey hybrid pump I now have a great winter backup option with the leather cup. In fact, I try to get all my pumps on leather cups… the Coleman neoprene always failed quicker, but they still sell leather replacement in all our hardware stores. My two Optimus 111s from the 70s are still on their original leathers, too. I suppose if you were going for extended trips in -20 or lower the arctic pump could add value, but it’s not affordable and really does seem like an expedition purchase for extended deep freeze trips. You could probably warm the pump in your hands for a minute or keep it wrapped in cloth in a ziploc in the bottom of the sleeping bag. But I’ve yet to have the pump fail in subzero. That’s my take!
I've used my old WL Int'l w/original gray/black pump a couple times in subzero F temps with no issues, snowmobiling into a couple areas. Did buy a new cold temp pump last year, don't know how much use it will see with all my antique and vintage stoves to select from. Duane
Thank you for sharing your experiences! And yes Coleman still sells a leather cup but in my view MSR does not. For now I have some msr leather cups so no problem Arctic pumps have very good coloring anyway...
