I don't bang the contamination control 'drum' very often. Reason being, I think the message has reached saturation point. by this I mean that anyone who wants to listen has at least heard the message. And that's a good thing.
But the other reason is, in isolation, contamination control is not a silver bullet for hydraulic equipment reliability. These days, best-practice contamination control is more like an accepted precondition for reliability. And given contemporary advances in technology for excluding and removing contaminants, it could be said that failure to control contamination is a failure of machine design, rather than a failure of maintenance.
That said, effective contamination control is not something to be taken for granted. And it never hurts to be reminded of the reliability benefits of kicking oil cleanliness up a notch. So when Antonio Dias de Toledo, one of my Hydraulics Pro Club members from Brazil, sent me this story I thought it worth sharing here:
"Our customer is a sugar cane mill, operating some 20+ sugar cane harvesters. The company I was working for installed low speed, high torque hydraulic motors on one machine transmission, as a prototype. At the same time we advised the customer they should improve their filtration, since we felt the original system was under specified - ISO 4406 figures were around 22/20. They agreed to upgrade the filtration with what we proposed.
Prior to the filtration upgrade, they were having regular pump failures. They told us they had to change three variable piston pumps per machine, per season, on average. After the new filtration system showed good results on the prototype machine, they upgraded another two machines in the first season. The ISO cleanliness code on these three machines was now 18/15.
With these numbers in hand, the end user convinced the harvester manufacturer to adopt the same transmission and hydraulic filtration system on the assembly line. By the fourth year that same sugar cane mill had about 15 machines with the new transmission and filtration system, and they were changing one variable piston pump per machine per three seasons - a nine fold increase in pump life!"
Sure, this is not a scientific study into the benefits of improving oil cleanliness, because clearly, other changes were made to the hydraulic circuit in addition to upgrading the filtration. And we're not told what influence (if any) these modifications had on other important operating parameters such as pressure and temperature. But what cannot be disputed is the drastic improvement in pump life.
The moral of this story is: hydraulic oil cleanliness is a key determinant of achieved component life. So leaving it to chance is a mistake. And to discover six other costly mistakes you want to be sure to avoid, get "Six Costly Mistakes Most Hydraulics Users Make... And How You Can Avoid Them!" available for FREE download here.