Hydraulic oil viscosity may not be the most exciting topic of discussion but using the correct viscosity for the operating conditions will help assure that you can get your work done and maximize the service life of your hydraulic power unit. In cold weather, oil that is too heavy may cause cavitation in the suction line and damage the pump. In extremely hot weather, oil that is too light may not properly lubricate the pump and hydraulic motor. This can lead to accelerated wear and premature failure.

Allowable oil viscosity range on Oilgear pumps and Char-Lynn motors is 65-2000 SUS. To stay within the required viscosity range, use the recommended grade of hydraulic oil listed in the CLIMAX Hydraulic Power Units Oil and Temperature chart. Remember, the hydraulic oil will warm up during use, sometimes as much as 80 to 90 degrees F.

Hydraulic Power Units Oil and Temperature chart

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