DEUTZ MWM 12420395 Complete Piston Ring Set

1. Basic Information

• Part Number: 12420395 (OEM original part, standard size)
• Type: Complete Piston Ring Set
• Applicable Models: MWM TBG620 V12/V16/V20, TBD620, TCG2020 series gas and diesel engines
• Matching Part: Compatible with Piston Assembly 12420394
• Composition: One set per cylinder, including compression rings and oil control ring
• Material: Alloy cast iron and ductile cast iron with chrome plating or nitriding surface treatment, featuring excellent wear resistance, high temperature resistance and sealing performance
• Original Reference Price (2026): Approximately €38–45 per set (exclusive of tax)

2. Functions & Features

1. Cylinder sealing: Prevent combustion gas from blowing into the crankcase and maintain stable cylinder pressure.
2. Oil control: Scrape excess lubricating oil off the cylinder wall to avoid oil burning.
3. Heat conduction: Transfer heat from the piston crown to the cylinder wall and lower piston operating temperature.
4. Superior performance: Surface reinforced with low friction coefficient, suitable for long-term heavy-duty operation.

3. Common Failures & Replacement

• Common issues: Ring wear, breakage, sticking and elasticity loss, which cause insufficient cylinder pressure, power loss, oil consumption and blue exhaust smoke.
• Replacement Interval: Replace together during major overhaul every 8000–10000 operating hours, or when the piston is disassembled.

4. Installation Instructions

1. Thoroughly clean carbon deposits and dirt from piston ring grooves and cylinder wall before installation.
2. Install compression rings and oil control ring in specified order. Stagger the ring gaps and do not align them.
3. Check the flexibility of each ring to ensure no sticking or deformation.
4. Apply special lubricant during assembly to prevent dry friction and damage.