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Chasing fuel-coolant crossover contamination or diagnosing persistent misfires on a Caterpillar C7, C9, or 3126B HEUI engine? Attempting to pull carbon-baked stainless injector cups or seat fresh sleeves using makeshift slide hammers or unguided drifts is a massive liability. The ATC 151-4832 / 221-9777 Master Remover & Installer Kit provides complete dual-tool in-vehicle extraction and parallel installation—saving hours of labor without pulling the cylinder head.

The Critical Physics of HEUI Injector Cup Sealing & Coolant-Fuel Crossover

On medium- and heavy-duty Caterpillar HEUI platforms—including the 3126B, C7, and C9 engines—the fuel injector cup (sleeve) forms a precise thermal and mechanical barrier between the high-pressure Hydraulic Electronic Unit Injector body and the engine's liquid coolant jacket. Over years of thermal cycling, fuel varnish, and electrolysis, the upper and lower sealing bands of the sleeve degrade. This degradation allows diesel fuel to bleed into the cooling system or engine coolant to weep into the fuel rail, causing rapid injector misfires, hard starts, and severe engine contamination. When replacing worn cups (such as Cat numbers 227-1200, 227-291, or 229-1490), pulling the cylinder head adds thousands of dollars in unnecessary gasket and shop labor costs. However, in-vehicle replacement using improvised tools is extremely hazardous. Off-angle extraction can score the cast-iron cylinder head bore well, while uneven installation force buckles the delicate sleeve lip—guaranteeing instant seal failure. The ATC 151-4832 / 221-9777 kit completely eliminates these risks. Featuring a heavy-duty collet-style thread puller mandrel and a parallel drive seating mandrel, it enables technicians to thread, extract, and seat fresh injector cups 100% perpendicular to the head deck directly in-frame.

• Targeted Cat HEUI Engine Fitment – Engineered custom explicitly for Caterpillar C7, C9, and 3126B HEUI diesel engine platforms.
• Direct OEM Dual-Tool Interchange – Serves as a direct functional replacement for original Caterpillar tool codes **151-4832** (remover) and **221-9777** (installer).
• Complete In-Vehicle Service Capability – Removes stuck injector cups and seats fresh sleeves directly in the chassis without pulling the cylinder head.
• Eliminates Fuel-Coolant Crossover – Restores OEM sealing integrity across cups like **227-1200**, **227-291**, and **229-1490** to prevent fluid cross-contamination.
• Heavy-Duty Industrial Tooling Package – Weighing a solid 8.00 lbs, this heat-treated alloy steel kit withstands continuous daily shop use in high-throughput fleet environments.

Stop Pulling Cylinder Heads for Sleeve Swaps. Command Total In-Frame Service Speed.

The ATC 151-4832 / 221-9777 Cat Injector Cup Remover & Installer Kit is an essential capital asset for commercial truck repair centers, municipal fleet depots, heavy equipment field service trucks, and independent diesel machine shops. Save thousands in labor costs, eliminate fluid contamination, and replace injector cups with complete mechanical authority using Apex.

Technical Specifications

Technical Metric	Value / Fitment Reference Guidelines
Target Engine Platforms	Caterpillar C7, C9, and 3126B HEUI Engines (Non-MEUI)
Primary Operational Functions	In-frame removal of old injector cups and installation of fresh sleeves
OEM Special Tool Cross Reference	Direct equivalent for Caterpillar 151-4832 (remover) & 221-9777 (installer)
Compatible Cup / Sleeve Part Numbers	Serves Cat cups 227-1200, 227-291, 229-1490, and equivalent HEUI sleeves
Tool Construction Metallurgy	Heat-treated high-tensile structural alloy steel
Total Package Shipping Weight	8.00 lbs (Substantial, shop-ready professional dual-tool kit)

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