21412527 Piston | Genuine Volvo Penta Part

🔧 Product Description

Precision hydraulic piston used inside the trim-cylinder top-end assembly of the Volvo Penta DPI-A sterndrive. It converts hydraulic pressure into linear movement and works with the specified seals, rod and cylinder components to raise, lower and hold the drive angle.

🚤 Compatibility

Typically suits:

• Volvo Penta D6-300A-G
• Volvo Penta D6-340A-G
• Volvo Penta D6-380A-G
• Volvo Penta DPI-A
• Volvo Penta D6-400A-G
• Volvo Penta D6-440A-G
• Volvo Penta D4-150A-G
• Volvo Penta D4-230A-G
• Volvo Penta D4-270A-G
• Volvo Penta D4-320A-G
• Volvo Penta D4-300A-G

• Engine Family: D, DPI
• HP Range: 150-440 HP

⚙️ Key Features

• Genuine Volvo Penta DPI-A hydraulic piston
• Internal component of the trim-cylinder top-end assembly
• Precision surface for hydraulic sealing and controlled movement
• Must be installed with correct seals and clean hydraulic fluid
• Drive product number and cylinder version control fitment
• Engine type: Volvo Penta DPI hydraulic sterndrive system
• 2 used per assembly

🔌 Function

Separates the pressure chambers inside the trim cylinder and transfers hydraulic force to the piston rod to position the sterndrive.

⚠️ Common Signs of Failure

• Drive drifts down or will not hold trim position
• Hydraulic bypass or slow movement
• Scored piston surface or damaged seal lands
• Contaminated oil and internal cylinder wear
• Uneven or jerky trim-cylinder operation

🛠️ Service Notes

• Measure the bore or liner and check it against the piston, using the size and class markings and the tolerances given in the workshop manual for your engine; pistons and bores are matched, and a worn bore needs attention before a new piston goes in
• Fit rings with the marked face up and the gaps staggered as the manual specifies, use a proper ring compressor, and oil the piston, rings and bore before entering them
• Observe the orientation markings on the piston and the pairing marks between piston and connecting rod so each assembly goes back in its own cylinder the right way round
• Use new pin retaining clips or circlips, check the pin fit and the rod bearing shells, and confirm the piston moves freely on the pin as the manual describes
• Where the manual calls for a piston protrusion or crown height check to select the gasket, carry it out before final assembly; then turn the engine over by hand to confirm free movement before starting

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21412527 → Supersedes 3861194 → Supersedes 872518

OEM / Related Numbers

• 3861194 earlier number superseded by this part
• 872518 earlier number superseded by this part

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging