In hydraulic rock drills and breakers, the accumulator is a small part with a big job. It is a pressure vessel holding nitrogen gas on one side and hydraulic oil on the other, separated by a diaphragm or bladder. It stores energy between impacts and releases it during the blow, smooths pressure peaks, and absorbs shocks before they reach hoses, valves and the carrier’s hydraulic system. When the accumulator loses its gas charge or its diaphragm is damaged, the whole machine feels it.
Five signs to watch for
- Weaker impact and lower productivity. Blows feel softer and drilling or breaking takes longer than usual.
- More vibration. Hoses shake noticeably and more vibration is felt in the boom and carrier.
- Pressure fluctuations and alarms. Pressure readings become unstable and hydraulic warnings appear more often.
- Louder noise and faster oil heating. The machine runs noisier and the hydraulic oil heats up faster.
- Oil leakage around the accumulator. Oil traces near the accumulator or on the gas side can point to a damaged diaphragm.
What causes accumulator failure?
- Wrong precharge pressure. The gas precharge is typically set at 0.6 to 0.9 times the minimum system pressure. If the precharge is too high, the accumulator can empty completely and damage the diaphragm.
- Excessive compression ratio. If the ratio between maximum system pressure and precharge is too high, the diaphragm or bladder is overstressed and its life is shortened.
- High oil temperature. Diaphragm and bladder materials degrade quickly at high temperatures, roughly above 80°C.
- Fast or incorrect charging. Filling nitrogen too quickly can chill and damage the diaphragm. Use only high-purity nitrogen, never compressed air, with the manufacturer-recommended charging kit.
Maintenance tips
- Check the gas precharge regularly against the value in the manufacturer’s manual. For hydraulic breakers, one manufacturer recommends checking every 3 months in heavy-duty work such as quarrying and mining, and every 6 months in lighter work.
- Keep hydraulic oil temperature under control.
- Replace the diaphragm or seal kit at the first signs of failure, before damage spreads to other components.
Regular accumulator checks are one of the simplest ways to protect impact performance and avoid costly downtime. Razor Spare supplies high-quality alternative accumulators, diaphragms and seal kits for rock drilling equipment.
Sources:
Power & Motion – “How to Avoid Hydraulic Accumulator Failure”, Brendan Casey, 17 November 2014.
https://www.powermotiontech.com/hydraulics-at-work/article/21884487/how-to-avoid-hydraulic-accumulator-failure
Beilite Machinery – “5 Things about Hydraulic Breaker Accumulator You Must Know”, 25 September 2025.
https://www.beilite.com/en/blog/info_itemid_13570.html
This article is an original summary prepared by Razor Spare based on the sources above.