Installing new injector cups into a dirty bore is a guaranteed way to cause coolant intrusion or combustion leaks. The ATC50136 (ZTSE 4304) is the professional brush set required to prep Ford 7.3L/6.0L and Navistar DT466/T444E engines for a perfect seal.

The Carbon Barrier: Why Scrubbing the Bore is Mandatory

On Navistar DT466 and Ford Powerstroke engines, the injector sleeve (cup) acts as the only shield between high-pressure combustion and the engine's coolant. If carbon, old sealant, or corrosion prevents the sleeve from seating flush against the cylinder head, the engine will suffer from "fuel in coolant" or "air in the fuel system."

• Seal Integrity Failure – Residual carbon acts as a shim, preventing the cup from seating at the correct depth.
• Coolant Intrusion – A poorly seated cup allows coolant to weep into the fuel gallery, potentially ruining every injector in the head.
• Combustion Gas Bypass – High-pressure gases can push past a dirty seal, causing erratic misfires and overhead smoke.
• OEM Reference Accuracy – Equivalent to ZTSE-4304, 303-D111, and 303-D112 tools used by dealership technicians.
• Heavy-Duty Bristles — Engineered to remove baked-on residue without scoring the precision-machined bore surfaces.

What is the ATC50136 Brush Set?

The ATC50136 DT Injector Sleeve Brush Set is a multi-component cleaning kit. It features precision-sized brushes designed to match the specific contours of the sleeve bore and the fuel gallery in Navistar and Ford diesel engines. It is a critical preparation tool for top-end maintenance and full rebuilds.

Massive Engine Compatibility

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