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Diagnosing fuel-in-coolant contamination, combustion gas blow-by, or misfire conditions on Caterpillar C7, C9, or 3126B HEUI diesel engines? Attempting to extract or seat brass and stainless steel injector sleeve cups using improvised slide hammers, cold chisels, or mallets creates catastrophic shop hazards. An un-centered puller gouges precision cylinder head aluminum or cast-iron bores, while hammering a new cup distorts the lower seating shoulder, leading to immediate coolant leaks and costly cylinder head removal. Engineered for commercial diesel technicians, mobile fleet service trucks, and heavy-duty engine rebuilders as a direct replacement for CAT OEM part numbers 151-4832 (remover) and 221-9777 (installer), the ATC 151-4832 / 221-9777 Master Kit delivers an all-in-one in-vehicle solution to pull and seat HEUI injector sleeve cups cleanly—without pulling the cylinder head off the engine block.

The Critical Physics of HEUI Sleeve Sealing & In-Vehicle Head Protection

Caterpillar C7, C9, and 3126B engines utilize Hydraulic Electronic Unit Injector (HEUI) systems where the fuel injector seats inside a replaceable sleeve cup (e.g., CAT parts 227-1200, 227-291, 229-1490). These cups pass directly through the cylinder head water jacket, isolating 30,000+ PSI hydraulic fuel pressure from high-temperature engine coolant. Over extended engine runtime, extreme thermal expansion, o-ring degradation, and coolant scale cause fuel to cross into the cooling system or combustion gas to press back into fuel galleries. Replacing these sleeves in-vehicle requires absolute mechanical precision. Generic pullers apply off-axis extraction forces that bind the cup, scarring the delicate aluminum counterbore wall. Furthermore, installing a fresh cup without parallel alignment crushes the cup lip, preventing a liquid-tight seal against the lower head land. The ATC 151-4832 / 221-9777 Master Kit completely eliminates these extraction and installation failures. Machined from high-tensile structural alloy steel, the puller tool threads securely into the old cup, pulling it dead-straight using smooth mechanical thread force. The driver tool then pilots squarely on the cylinder head deck, pressing the fresh sleeve cup down evenly until it seats 100% flush against the factory bottom shoulder with zero wall contact or metal distortion.

• Targeted CAT HEUI Platform Coverage – Purpose-built specifically for Caterpillar C7, C9, and 3126B HEUI diesel engine families (Services cups 227-1200, 227-291, 229-1490; not for MEUI variants).
• Direct OEM Factory Tool Interchange – Direct high-strength replacement for CAT OEM specialty tool part numbers **151-4832** (remover) and **221-9777** (installer) (ATC151-4832 / 221-9777).
• 100% In-Vehicle Service Capability – Removes and installs injector sleeve cups directly on the engine in the chassis, saving 10+ hours of labor by avoiding cylinder head removal.
• Protects Precision Head Bores & Counterbores – Dual-function piloted design prevents tool tilt, bore gouging, and lower landing shoulder distortion.
• Heavy-Duty Commercial Grade Steel Build – Substantial 8.00 lbs solid structural alloy steel construction built for continuous daily use in commercial overhaul bays and field service trucks.

Stop Pulling Cylinder Heads. Command Total CAT HEUI Injector Service Precision.

The Injector Cup Remover & Installer Kit – ATC 151-4832 / 221-9777 for CAT C7 | C9 | 3126B is an essential capital asset for commercial truck repair centers, Caterpillar dealership service bays, fleet maintenance facilities, and heavy diesel rebuilders. Prevent fuel-coolant crossover, save massive shop labor hours, and service HEUI injector cups with complete mechanical authority using Apex tools.

Technical Specifications

Technical Metric	Value / Fitment Reference Guidelines
Target Engine Platforms	Caterpillar C7, C9, and 3126B HEUI Engines (Excludes MEUI Mechanical Systems)
Target Injector Cup Part Numbers	CAT 227-1200, 227-291, 229-1490 and Equivalent HEUI Sleeve Cups
Primary Operational Function	In-vehicle extraction and precision driving of HEUI fuel injector sleeve cups
Specialty Tool Cross Reference	Direct replacement for Caterpillar OEM 151-4832 (Remover) & 221-9777 (Installer)
Part / Model Reference Number	ATC 151-4832 / 221-9777 (ATC151-4832 / 221-9777)
Construction Metallurgy	High-tensile precision-machined structural alloy tool steel
Total Package Shipping Weight	8.00 lbs (Complete dual-tool commercial shop service kit)

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