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2016 cat 311flrr air leak sound near accumulator/accumulator area

Kdigger · 2025-09-23 22:06

Hey guys. I didn’t know who to specifically ask but I keep seeing nige answer a lot of questions well here. I’m open anyones input I’m relatively new here. I couldn’t find anyone having this particular noise with accumulator failure in any other thread other than how to do the test I had performed. My 2016 cat 311flrr Vin KCW00396 excavator I just started noticing an air leak sound coming from the hydraulic manifold compartment where the accumulator is located. It sounds like it is coming from the accumulator/accumulator area. I sprayed accumulator and other surrounding ports and hoses with soap to see if there any bubbles but I didn’t see any. Machine seems to be running pretty normal as it is a new to me machine with 3500hrs. I did the test of having the machine running with the bucket 3 feet off the ground. I shut the machine off and turn back on and it does not lower the boom. There are no error codes stored or current codes showing on the display or in the service tab. My accumulator seems to be a sealed pre charged unit because I didn’t see a port on the top like some have to check nitrogen pressure. Is there anything else I should check or am I safe to assume it’s probably the accumulator. The machine might be a little jerkier than when I first got it when doing multiple movements at the same time but not really bad at all, it’s operating pretty normal. Can I hurt anything if I am using the machine until I can determine it is definitely the accumulator and I can get a new one? Appreciate any input

Replies2
  1. #1Nige2025-09-24 04:57

    From your testing it seems that you have confirmed that the accumulator has failed. The noise you are hearing might well be coming from the damaged accumulator. The only need/use for the accumulator is to help in lowering any raised equipment if the engine stops for whatever reason. If you can find a plug of the correct thread you could remove the accumulator and plug the port temporarily as a test to see if the noise disappears. AFAIK service replacement accumulators are a slightly different design and come uncharged, meaning that they have to be charged with nitrogen after installation.

  2. #2Kdigger2025-09-29 19:51

    Awesome thanks for your help!