ISUZU 4HK1 6HK1 Nozzle Holder Sleeve 8-97606661-0 — Precision-Machined Brass Injector Seal Sleeve with 200 Bar Pressure Rating and Direct OEM Fit

The Nozzle Holder Sleeve with OEM number 8-97606661-0 — cross-referencing to 8976066610 / 8-98018462-0 / 8980184620 — is a precision-engineered brass sealing component for the cylinder head of ISUZU 4HK1 and 6HK1 common rail diesel engines. This sleeve creates a sealed passage between the injector nozzle and the combustion chamber, preventing high-pressure combustion gas leakage while blocking coolant from entering the injector bore area.

The nozzle holder sleeve is installed in the injector bore of the cylinder head. Its core functions include: precisely positioning the injector nozzle, sealing the combustion chamber against gas blow-by, isolating the injector from engine coolant, and protecting the injector tip from carbon buildup and corrosion. Manufactured from precision-machined brass, the sleeve offers corrosion resistance and high strength, designed to withstand the extreme conditions of common rail injection systems.

• Material & Construction: Precision-machined brass, cylindrical with flared end and threaded interface — corrosion-resistant and high-strength. Material certificate available upon request.
• Pressure Rating: 200 bar (2,900 PSI) — withstands common rail injection pressures. Based on product specification data.
• Temperature Range: -40 °C to 150°C (-40°F to 302°F) — based on product specification data.
• Installation Fitment: Direct replacement for OEM sleeve in ISUZU 4HK1 / 6HK1 cylinder head injector bores — installation success rate to be supplemented from actual repair order data.
• OEM Cross-Reference Verified: Replaces 8976066610 / 8980184621 / 8-98018462-0 / 8980184620 / 897606-6610

• Abnormal coolant level drop; bubbles or turbulence observed in coolant reservoir
• Diesel odor in engine oil or abnormal oil level rise (fuel contaminating oil system)
• White smoke from exhaust, reduced engine power, or rough idle
• Carbon tracks or discoloration at injector bottom (typical sign of failed copper gasket)
• Leakage at nozzle holder sleeve area during cylinder head pressure test

⚠️ The above QC items are industry-standard recommendations. Third-party inspection reports or bench test data should be prioritized if available.

(Reference workshop manual):

1. After removing the old sleeve, thoroughly clean the cylinder head bore — free of carbon, corrosion, or residual sealant
2. Inspect copper gasket seat surface flatness — sealing surface must be perfectly clean; old copper gasket can be hand-lapped with fine compound to clean the seat surface
3. When installing the new nozzle holder sleeve, ensure the copper gasket at the sleeve bottom is correctly seated
4. Tighten injector clamp bolts to ISUZU-specified torque — note this is a low-torque specification; do not over-tighten
5. Perform cylinder head pressure test after installation to confirm no leakage
6. Recommend simultaneous replacement of copper gaskets and O-rings

• Replace all nozzle holder sleeves when servicing cylinder head or performing valve work
• Inspect sleeve sealing immediately if abnormal coolant consumption or oil contamination occurs
• Check every 100,000-150,000 km or per engine overhaul interval