Having the right filters in the right places is essential to the success of the contamination control effort. But it can be easily compromised by buying filters on price alone. Like any other aftermarket or non-genuine part, replacement filter elements vary in both quality and price. And there are two potential risks with installing 'will fit' filter elements.
The first is, if the element is not structurally the same. For example, as a young man working on the family farm I can remember installing a non-genuine transmission oil filter on a Deutz tractor. It was a spin-on element which was correctly cross-referenced by its aftermarket manufacturer. It looked the same and fitted the same. But what was not obvious, was the more expensive genuine element had a bypass valve built into it. The non-genuine element did not.
On one cold morning, with no bypass installed, the high pressure drop across the element caused it to spin loose. Luckily, the filter was mounted just behind the steps up to the cabin and the so the operator noticed the problem before he started work for the day. If he hadn't picked up the problem when he did, it's likely all the oil would have been pumped out of the transmission and the transmission destroyed. Suffice to say we always used the genuine filter in that application from then on.
The second issue is, will a cheaper replacement element filter as well the original, and how can you tell? If you take regular particle counts on the machine in question and you change the filter elements based on condition - i.e. when they are clogged, and not on hours in service, you'll soon know if the cheaper filter element is false economy.
Because it's not the absolute price of the filter element that matters. It's the dollars per gram or ounce of dirt captured and retained that matters. And it's this measure which enables you to compare 'apples to apples'. By way of simple illustration, if an element is half the price, but you have to change it twice as often to maintain your target fluid cleanliness level, then the cheaper element is definitely false economy.
The flipside of this is if you don't take regular particle counts and you change filter elements based on an arbitrary number of hours in service recommended by the machine manufacturer, then buying filter elements on price alone can be a dangerous strategy.
In this situation you are totally reliant on the machine manufacturer's recommended change interval, which is hopefully based on some testing the machine manufacturer has carried out using their 'genuine' filter elements. If you switch filter elements and adhere to the same change interval, you're even more in the dark than you were before.
To sum up: being cheap about filtration is a mistake. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, get "Six Costly Mistakes Most Hydraulics Users Make... And How You Can Avoid Them!" available for FREE download here.