20412762 O-Ring | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta lower cylinder-liner O-ring used to seal wet liners into the cylinder block on D5 and D7 engines. Two O-rings are fitted per cylinder, giving eight on four-cylinder engines and twelve on six-cylinder engines.

🚤 Compatibility

• Engine Family: D, TD, TAD, MD

Full model list at the end of this description.

⚙️ Key Features

• Wet-liner lower sealing O-ring
• Two used per cylinder
• Eight required on D5 four-cylinder engines and twelve on D7 six-cylinder engines
• Separates engine coolant from the crankcase
• Replace all liner seals during cylinder overhaul
• Engine type: Volvo Penta 5- and 7-litre industrial diesel

🔌 Function

Seals the lower wet-liner bore so coolant cannot enter the crankcase.

⚠️ Common Signs of Failure

• Coolant in the engine oil
• Oil level rising unexpectedly
• Coolant loss with no external leak
• O-ring cuts, hardening or extrusion
• Corrosion in the liner-seal bore

🛠️ Service Notes

• Always fit a new O-ring — never refit one that has been removed, as it has already taken a set in its groove
• Clean the groove and both sealing faces and check them for nicks, scoring and corrosion pitting; a damaged groove will leak however good the new seal is
• Smear the ring with a little clean lubricant compatible with the fluid it seals, then roll it into place by hand so it sits untwisted and fully in its groove
• Never lever an O-ring over a sharp edge or thread with a screwdriver; use a blunt plastic tool and protect any edge the ring has to pass
• Assemble the joint squarely and tighten to the figure and sequence given in the workshop manual for your engine — over-tightening extrudes the ring and causes the very leak you were curing

🔄 Supersession & Cross Reference

OEM / Related Numbers

• 3843536 - related cylinder-liner and piston kits where specified
• 3842448 - related cylinder-liner and piston kits where specified

📦 Condition

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

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta D8A2-A MP, D8A5-A MH, D8A6-A MH, D8A4-A MP, D8A1-A MP, D8A3-A MP
• Volvo Penta D7A-B TA, D7A-T, D7A-TA, D7C-B TA, D7C-TA
• Volvo Penta D5A-B TA, D5A-T, D5A-TA
• Volvo Penta MD2010, MD2010B
• Volvo Penta TAD520GE, TAD520VE
• Volvo Penta TAD530GE MECH, TAD530GE EDC4
• Volvo Penta TAD531GE MECH, TAD531GE EDC4
• Volvo Penta TAD720GE, TAD720VE
• Volvo Penta TAD721GE, TAD721VE
• Volvo Penta TAD722GE, TAD722VE
• Volvo Penta TAD730GE MECH, TAD730GE EDC4
• Volvo Penta TAD731GE MECH, TAD731GE EDC4
• Volvo Penta TAD750GE, TAD750VE
• Volvo Penta TD520GE, TD520VE
• Volvo Penta TD720GE, TD720VE PP
• Volvo Penta TAD532GE EDC4
• Volvo Penta TAD550GE
• Volvo Penta TAD551GE
• Volvo Penta TAD560VE
• Volvo Penta TAD561VE
• Volvo Penta TAD732GE EDC4
• Volvo Penta TAD733GE EDC4
• Volvo Penta TAD734GE
• Volvo Penta TAD751GE
• Volvo Penta TAD752GE
• Volvo Penta TAD753GE
• Volvo Penta TAD754GE
• Volvo Penta TAD760VE
• Volvo Penta TAD761VE
• Volvo Penta TAD762VE
• Volvo Penta TAD763VE
• Volvo Penta TAD764VE
• Volvo Penta TAD765VE