129403-18050 Turbocharger for Kobelco SK025 SK027

129403-18050 RHB31 Turbocharger for Yanmar 3TN84TL Engine

The 129403-18050 RHB31 turbocharger is supplied for Yanmar 3TN84TL, 3TN84TL-R2B and 3TN84T diesel engine applications. It is commonly checked for Kobelco SK025, SK027 and related compact excavator repair. This turbocharger is used to restore boost pressure, improve air intake volume and support stable engine output when the old turbocharger has weak boost, oil leakage, abnormal noise, damaged wheel blades or excessive shaft play.

This replacement turbocharger should be matched by the old turbocharger number, turbo model, engine model and removed sample. Since RHB31 turbochargers can have different compressor housing, turbine housing, outlet direction and oil pipe positions, the old turbocharger tag and sample photos should be checked before order confirmation.

Main Part Number and Ref Cross

The main part number is 129403-18050. The no-hyphen format 12940318050 may appear in buyer searches or old purchase records. Ref Cross numbers such as 129189-18010, 12918918010, VC110021, VA110021, VB110021 and VB110024 can be used for inquiry matching. Final confirmation should still be based on the old turbocharger nameplate, engine model and physical housing comparison before shipment.

Part Number: 129403-18050

Ref Cross: 12940318050 / 129189-18010 / 12918918010 / VC110021 / VA110021 / VB110021 / VB110024

Turbo Model: RHB31 series turbocharger

Engine Model: Yanmar 3TN84TL / 3TN84TL-R2B / 3TN84T diesel engine

Main Application: Kobelco SK025 / SK027 compact excavator

Related Application: Yanmar 3TN82TE, 3TN84TEKR, 4TN78TL and related small diesel engine applications, verify by old turbo tag and sample photos

Application Matching Notes

For Kobelco SK025 and SK027 applications, the safest confirmation method is to check the Yanmar engine model together with the old turbocharger number. Machine model alone is not enough for final matching because compact excavators can have different engine versions, previous replacement history or non-original turbocharger changes.

Machine Check: Confirm Kobelco SK025, SK027 or the actual compact excavator model from the buyer.

Engine Check: Confirm Yanmar 3TN84TL, 3TN84TL-R2B, 3TN84T or the actual engine plate model.

Turbo Tag Check: Check for 129403-18050, 12940318050, 129189-18010, VC110021, VA110021, VB110021, VB110024 or RHB31 on the old turbocharger tag.

Housing Check: Compare compressor housing, turbine housing, outlet direction, flange type and mounting layout.

Oil Line Check: Confirm oil inlet, oil outlet, pipe position and return line direction.

Photo Check: Provide clear photos of the nameplate side, compressor side, turbine side and mounting side before quotation.

Common Replacement Conditions

A worn 129403-18050 RHB31 turbocharger can cause low boost pressure, black smoke, weak acceleration, oil leakage, abnormal turbo noise, damaged compressor wheel or excessive shaft clearance. Before replacing the turbocharger, the air intake, exhaust and lubrication systems should be checked to reduce the risk of repeat turbo failure.

Low Boost or Black Smoke: Check the air filter, intake pipe, compressor wheel condition and boost leakage.

Weak Engine Power: Inspect the compressor wheel, turbine wheel, exhaust leak, boost hose and fuel injection condition.

Oil Leakage: Check the oil feed line, oil return line and crankcase ventilation. A blocked oil return line can cause oil leakage at the turbocharger seal area.

Abnormal Turbo Noise: Check shaft play, bearing wear, wheel contact marks and signs of contaminated oil or foreign object damage.

Inspection Before Installation

Before replacing the 129403-18050 turbocharger, inspect the air filter, air intake pipe, exhaust manifold, oil feed line and oil return line. Turbocharger damage is often caused by dirty oil, blocked oil return, air restriction, exhaust leakage or foreign object damage from the intake side.

During installation, add clean engine oil into the turbocharger oil inlet and rotate the compressor wheel by hand before the first engine start. After installation, check for oil leakage, abnormal turbo noise, black smoke, blue smoke, weak boost and unstable engine response during low-speed and working-speed testing.

FAQ

Is 129403-18050 the main part number for this product?

Yes. 129403-18050 is the main part number for this RHB31 turbocharger direction. The no-hyphen format 12940318050 can also be used for inquiry matching.

Can 129189-18010 be used as Ref Cross?

Yes. 129189-18010 can be used as a Ref Cross reference for this 129403-18050 turbocharger direction. Final matching should still be confirmed by the old turbocharger tag and sample photos.

Can VC110021 be used for matching?

Yes. VC110021 can be used as a checking reference when the old turbocharger tag, engine model and removed sample match this RHB31 turbocharger direction.

Is this turbocharger for Kobelco SK025 or SK027?

It can be checked for Kobelco SK025 and SK027 applications when the Yanmar engine model, old turbocharger number and sample photos match this 129403-18050 / RHB31 direction.

What should I provide before ordering?

Please provide the old turbocharger part number, turbo nameplate photo, engine model, equipment model and clear photos of the removed turbocharger.