Usage:
All Caterpillar Machines Equipped with Piston and Bladder Type Accumulators
Caterpillar machines equipped with hydraulic accumulators are shipped from the factory with the accumulator fully pre-charged with dry nitrogen gas. Accumulator pre-charge will decrease in operation. Nitrogen gas will be lost by permeation of the gas through the bladder of a bladder accumulator, and past the piston seals of a piston accumulator through the wiping action of the piston. Pre-charge loss is related to the activity level of the accumulator circuit. Pre-charge pressure must be checked and adjusted at regular intervals.
Low pre-charge pressure can cause system performance deterioration and damage to the bladder of a bladder type accumulator. The service interval for checking pre-charge is every 6 months or every 500 hours, whichever comes first. Refer to the appropriate machine service manual for correct checking and charging procedure.
New service replacement accumulators are being released for some piston and bladder type accumulators. Federal regulations dictate that certain air carriers cannot transport a pressurized container such as a pre-charged accumulator. Accumulators that are not pre-charged have been released as service replacements for the factory installed accumulator where needed. The following chart indicates the new service replacement accumulators. Refer to the appropriate machine service manual for accumulator charging instruction.
Refer to the appropriate machine service manual for accumulator charging instruction.