It's happened again!

In the 70's while I was working at a farm equipment dealer, I remember two persons ultimately having injector pump trouble, after taking off the Stanadyne clamp on, square filter, shaking it out, and putting it back on!

A neighbor just did the same thing. This, after the tractor quit, because there was so much crud in the filter! I don't know if I got him stopped in time or not, yet.

What is there about these filters which leads to this behavior?

Best thing that ever happened here was we went from a below ground tank that had no filter on the pump to our current above ground tank with filter on the pump. Tank filter gets changed every spring so filters last much longer. To address the topic I would never do what your neighbor did. Those filters are very reasonable in price so there is always an extra or two on the shelf.

(quoted from post at 18:13:17 09/02/19) In the 70's while I was working at a farm equipment dealer, I remember two persons ultimately having injector pump trouble, after taking off the Stanadyne clamp on, square filter, shaking it out, and putting it back on!

A neighbor just did the same thing. This, after the tractor quit, because there was so much crud in the filter! I don't know if I got him stopped in time or not, yet.

What is there about these filters which leads to this behavior?

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"What is there about these filters which leads to this behavior?"

NOTHING or a "myth".

There's several ports on those filters, and there's no way that I can see that removing 'em and shaking them could possibly cause cross contamination between the "dirty side" and the "clean side" to the point it would "kill" an injection pump.

If someone has a better insight into thjis, it will be interesting to read their reply!

I'm going to offer this analogy: When we were teenagers drinking on the sly, we had a fairly good liklihood of drinking too much and having various problems as a result. One problem was apt to be an uncomfortable stomach. Kids who were perhaps a year or two older would offer the advice to "never mix your alcohol!!" "If you start with beer stick with beer, don't drink hard liquor on top of beer". Well as you get older and wiser you realize that it wasn't what you drank but how much you drank. You were not likely to be drinking different types of alcohol unless you were drinking more than you should. So I suspect that the real problem wasn't the filter but a combination of dirty fuel and rare filter changes, along with perhaps sloppy handling of the filters.

During the same time frame, I don't recall any similar instance with a spin on filter. I often wondered if dumping and re-using it had to do with the early/glass/see through Stanadyne filter vs a spin on you couldn't see through? I don't how it happened either, but from my experience it did happen, so no myth here. Or did crud just get by the square filter anyway, eventually causing pump problems? I don't know. I do know it made me leery of the Stanadyne filters. That, and watching a fellow bust one by pumping the hand primer, and also watching one draw in air bubbles on a cold winter day.

I do not think those filters cause anymore trouble than any others. I like how easy they are to change and when bought in bulk they cost under $10 each. So why not replace them regularly???

One thing that can happen real easy on these filters, The set out from the bracket about 1/8 of an inch. They will get dirt built up between the filter and the filter mount. IF you do not clean that dirt off the bracket/mount or the filter, you could easily get dirt into the fuel system.

I have dumped water out of them and reinstalled them. I made sure the filter back and the filter mount was clean when I did that.

Some filters shaking like that can cause the paper element in them to crack/break letting dirt through to the pump. Also if the filter is not kept clean till used that can also allow dirt to contaminate the pump.
We have always tried very hard to buy clean fuel and then keep it clean just as it says on the cap. I guess it has worked for us. I have only had one injector pump worked on and that was when the flex ring went bad in my pick up 20 years ago.

(quoted from post at 19:57:35 09/02/19) During the same time frame, I don't recall any similar instance with a spin on filter. I often wondered if dumping and re-using it had to do with the early/glass/see through Stanadyne filter vs a spin on you couldn't see through? I don't how it happened either, but from my experience it did happen, so no myth here. Or did crud just get by the square filter anyway, eventually causing pump problems? I don't know. I do know it made me leery of the Stanadyne filters. That, and watching a fellow bust one by pumping the hand primer, and also watching one draw in air bubbles on a cold winter day.

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I have owned/own a number of machines with those filters, plus I do repair work, and have removed filters and set them aside (where they drain) and put 'em back on many times with no issues.

Of course, I do make sure the grommets on the filters and the mounting surfaces are clean.

I have no reason to believe Stanadyne makes an inferior product, and it's any more likely for the filter material to be damaged or "crack", as someone wrote, vs. any other fuel filter.

Interesting. It seems then that it's a generally accepted practice to re install these filters. Do you do the same with spin on filters? I have always replaced a filter once it's been disturbed/used.