Seal ring damage or wear; Internal damper parts wear or damage; Plunger dirt, fouling, damage, or wear; Plunger distance 'A' less than 18.3 mm (0.72 inch)
Get a diagnosis walkthrough for 1078-011 on your specific Caterpillar Inc. unit — cited to the OEM manual, not a forum guess.
Free account required — we'll bring your question with you.