MSR Miniworks EX - filter cracked

9:41 p.m. on August 14, 2011 (EDT)
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The discussion in the Gear Selection thread reminded me that I still needed to clean up my Miniworks since I used it last weekend  (oops!).  After disassembling the unit and starting in on cleaning the filter, I noticed it's cracked.  Yikes!! it may well have been like that on my recent trip & I just didn't notice.  It looks all chipped up, too, which is a mystery to me since I thought I was handling it carefully.

So I'm checking out replacement filter prices ... and notice there's also a "maintenance kit" available with spare o-rings & such.

A couple questions for those of you who've had your Miniworks for a number of years:

- how often do you replace the o-rings & other internal pieces?

- have you had any problems with the overall plastic casing or other external parts breaking with age?

I'm contemplating the cost of the filter + maint kit vs possibly having to replace the whole unit at some point.



8:09 a.m. on August 15, 2011 (EDT)
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I am going to start out by saying that the only filter element I have ever seen crack was mine, and thats because It fell about 30ft and then rolled another 20 or so haha. That was completely my fault though.

I am curious to how it broke, unless they are frozen or dropped really hard i have never seen one break.(and this is being around alot of them while in the military where no one is gentle on their gear)

I have never had to replace one of the parts of my miniworks prematurely other than the element and the main o-ring that goes on the filter element itself. New elements come with that o-ring though.

As long as you clean the other valves on occassion to keep debris from tearing them up that should last close to forever. The other o-rings depends on how often you have to uncompress them to clean the valves. Depending on your water, you may have to clean those valves every trip or every year. I just give mine a good cleaning once a year unless required sooner. I typically replace all o-rings when i replace a filter element, which for me is about every 5-6 years. I have never had the casing or an external part break.

I highly suggest to everyone to clean your filter with a toothbrush vice the green scrubby. Someone hear on trailspace recommend that a few weeks ago and that is an awesome idea I must say! Very happy with it. Really preserves filter life.

And lastly it may be because of the picture itself, but that filter element looks very oddly shaped, the filter body in the center is waaaaayyyy thinner than the rest of the filter. Which may have lead up to it cracking due to the difference between the center and ends. Always clean the filter element evenly, and use that little red disk to measure the element. It definitely looks like your disk would tell you the center of that element is done.

11:27 a.m. on August 15, 2011 (EDT)
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It looks alot like a fracture from freezing. May not be, but the fracture doesn't seem to have an impact origination point, and is widest in the middle of the crack. This suggest to me it was created from the even buildup of internal expansion pressure exerted from freezing. 


10:10 p.m. on August 15, 2011 (EDT)
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TheRambler, Gonzan, it's interesting that you both suspected freezing.  I've given this a lot of thought, and am quite sure I haven't had the filter out where it would have frozen.    One thing that puzzles me is that there are chips in the surface - I'm quite sure I have been very careful of the filter when I've had it out of the case for cleaning.  Though it's difficult to see in the photo, one of the larger chips is right on the crack.

Anyway, thanks for your feedback.  Points definitely noted about cleaning technique - and I will use a toothbrush from here on.  The cartridge does have a concave shape, so presumably I focused too much on the mid section while scrubbing it.

I ordered a replacement cartridge today.  I've held off on the maintenance kit for now, though it probably wouldn't be a bad idea to have on hand in case I lose one of the tiny pieces when I have the unit apart for cleaning :).

I wonder how many little critters crept thru that crack and into the ~6 liters of water I drank from that filter last weekend...  the creek from which I filtered comes down from a heavily used lakes area :(.




7:00 a.m. on August 16, 2011 (EDT)
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You will find out in about a week! haha =P

12:43 a.m. on September 19, 2011 (EDT)
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I have had my Miniworks for about 12+ years and have yet to replace the filter.  Although I did just by a new one.  I normally get about a gallon of water before I need to clean it.   I never push hard with the little green pad and I am careful to work it evenly up and down to it wears evenly.   I read the instructions again this summer (Not sure if I ever did before) and learned about home cleaning and evened boiled the filter like it said in the instructions. 

Given the nature of the crack I am wondering if it got dropped while it was in the pump?  With a thinned center maybe it just got banged around and developed a stress crack and then it grew.  Not really sure if it did not freeze.  But regardless I think you on track with a replacement filter. 

As for the ring and other parts, I only disassemble it and clean all the parts at home, never in the field.  Well at least not yet.  And if I am cleaning the filter I use clean water and then pump some onto the ground to "Wash it out" after putting it back together.  So far it's worked like a champ, but I am starting to think about those gravity systems....  Mostly when I am pumping and pumping .....  Repeat repeat :)


7:23 a.m. on September 19, 2011 (EDT)
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I also use a cutdown toothbrush to clean the filter element. I do this in the field and it seems to be a bit easier on the element than the little green scrubby which in turn will help maximize the lifespan of your element.

I use the same one I use to brush my teeth... J/k, I use someone elses... :)

Every now and then you will have to use the scrubby; just be easy with it.

10:07 p.m. on September 19, 2011 (EDT)
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Same here, had mine about 12 years now. Never replaced anything on it yet. After any trip, when at home, I take it apart and clean & dry everything. Every once in a while I give the o-rings a little food grade silicone grease. The lubrication is important to keep them from twisting/tearing/stretching as everything is put together & it keeps the rubber pliable. I guess I'm lucky in the water sources I choose, or that I'm not limited to mud holes, I hardly ever clean the element beyond a good rinse at home.

Been thinking about the maint. kit lately, just to have it on me when I need it. One thing I've learned from diving, you never know when an o-ring is going to fail, and if you don't have a replacement on you, it could be trip over.

I like the toothbrush idea. Maybe a new one though.. without anyone's mouth bacteria on it.

April 26, 2018
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