Checking for pre-charge without a check kit can be a quick and easy process that does not require any tools. It is, often, simple to do and can immediately give a thumbs up or down to the integrity of the accumulator. It’s not as accurate as using a pre-charge pressure check/charge kit, but it normally suffices.
Knowing how to do this can be especially helpful when making periodic maintenance checks or for a technician trying to troubleshoot a system that has an accumulator on it, but they do not have a check/charge kit with them.
This is a critical procedure for small accumulators. Since some nitrogen escapes every time the pre-charge is checked, the practice of tapping into the nitrogen charge can cause the pre-charge to go low.
Sometimes, technicians make a mistake by not relieving all hydraulic pressure before using a nitrogen gas charge check kit, and they get a false reading. By dumping the hydraulic pressure as part of the procedure, it ensures that the gas charge is not being influenced by hydraulic pressure in the system.
We recommend using both methods on most accumulator systems. It’s a viable double-check and a good reference for future checks.
