It is the additive package that enables a water glycol fluid to perform in today's high performance hydraulic hardware. Positive head, or mounting the pump below fluid level allowing the weight of the fluid to supercharge the pump inlet, is an excellent way to offset the effects of water's high vapour pressure in a water glycol fluid. Inlet strainer should be no finer than 100 mesh, with 60 mesh being optimum. If a system has pressure side filtration, good return line filtration is in place, and a filter breather is being used, no inlet strainer is required. This will eliminate any possibility of cavitation due to strainer clogging.
High viscosity is an indication that water is being lost, normally through evaporation.
This is a natural occurrence when hydraulic reservoirs are vented to the atmosphere, and when systems are overheating. Fahrenheit above the viscosity of new fluid, water adjustments should be made. It is crucial that water used for adjustments be distilled, soft, deinionized or boiler condensate. Divalent metal ions like calcium and magnesium, typically found in tap and spring water, will cause the lubrication additives in today's water glycol fluids to become solid and permanently ineffective as additives. Fahrenheit less than the viscosity of the new fluid - in a water glycol fluid is usually a result of too much water in the fluid.