1545178 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

This is a genuine Volvo Penta valve seat in the 0,20mm oversize dimension, supplied within the Engine system group for cylinder head service on the MD30/MD40 and TMD/TAMD 30 and 40 series marine diesels. The oversize dimension is what sets it apart from the standard-size seat, and it is intended for heads that have been machined out to accept a larger insert during rebuild. It supersedes the earlier exhaust valve seat part number 1542404.

🚤 Compatibility

Typically suits:

• Volvo Penta MD40A
• Volvo Penta TMD40A
• Volvo Penta TMD40B
• Volvo Penta TMD40C
• Volvo Penta AQAD40B
• Volvo Penta AQAD30A
• Volvo Penta MD30A
• Volvo Penta TAMD30A
• Volvo Penta TD30A
• Volvo Penta TMD30A
• Volvo Penta AQAD40A
• Volvo Penta AQD40A
• Volvo Penta TD40A
• Volvo Penta TAMD40A
• Volvo Penta TAMD40B

• Engine Family: MD, TMD, AQAD, TAMD, TD, AQD
• HP Range: Approximately 62-165 HP
• Year Range: Approximately 1973 - late 1980s

⚙️ Key Features

• OEM Volvo Penta part number 1545178
• Oversize dimension: 0,20mm
• System group: Engine
• Net weight approximately 0.029 kg
• Supersedes previous part number 1542404 (exhaust valve seat)
• Fits MD30, MD40, TD30, TD40, TMD30, TMD40, TAMD30, TAMD40, AQAD30, AQAD40 and AQD40 series marine diesel engines
• Engine type: Four- and six-cylinder marine diesel

🔌 Function

The valve seat is the machined insert pressed into the cylinder head against which the valve face closes, forming the combustion chamber seal and transferring heat from the valve into the head. The 0,20mm oversize version restores correct seat fit in a cylinder head whose original seat bore has been machined oversize during overhaul.

⚠️ Common Signs of Failure

• Loss of compression, hard starting or poor running on one or more cylinders
• Visible pitting, burning or recession of the seat face on inspection
• Valve seat leakage confirmed during a pressure or vacuum test of the head
• Loose or dropped seat insert causing tapping noise and possible valve or piston damage
• Excessive valve stem protrusion or loss of valve clearance from progressive seat recession

🛠️ Service Notes

• Use only where the cylinder-head recess has been machined for the +0.20mm repair-size insert.
• After fitting, machine the seat to the specified angle, width, concentricity and valve-recession dimensions.

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 1545178 → Supersedes 1542404

OEM / Related Numbers

• 1542404 earlier number superseded by this part
• 1545177 - standard-size exhaust seat; not interchangeable where the +0.20mm repair size is required

📦 Condition

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