OTC Compression Tester Kit 0–300 psi, 25" Flex Hose with Multiple Adapters and Hard Case

OTC 5606 Compression Tester Kit is a professional-grade toolset for diagnosing gasoline engines, delivering accurate 0–300 psi readings with versatile adapters and a durable storage case.

Whether you're troubleshooting a passenger car, motorcycle, marine outboard, or small-engine equipment, a reliable compression test quickly reveals cylinder sealing and valve condition. The OTC 5606 pairs a large dual-scale gauge and extended flex hose with multiple thread adapters so you can test a wide variety of spark plug and threaded-plug seats without additional tools.

How accurate and readable is the gauge?

The kit uses a 2.5-inch dual-scale gauge that displays readings in psi and kPa for straightforward interpretation. Its chrome bezel and protective rubber boot help preserve the gauge face against shop impacts while the zero-adjust feature lets you re-zero for repeatable tests.

• Range: 0–300 psi and 0–2100 kPa
• 2.5" dial for easy visibility
• Chrome bezel and rugged protective boot
• Manual zero-adjust for calibration on-site

What engine types and spark plug seats will this kit work on?

Adapters included with the 5606 accommodate most gasoline engine spark plug and threaded-plug seats, covering domestic, import, motorcycle, marine, and small engines. The adapter set fits both flat and tapered seat plugs so you can move between engine families without swapping kits.

• Adapters: 10mm, 12mm, 18mm thread sizes
• 14mm flex fittings — standard and long-reach 12" versions
• Adapters compatible with flat and tapered seats
• Works across a wide range of gasoline engines

How does the hose and coupler design improve testing in tight spaces?

The extra-long 25" flex hose lets you position the gauge outside crowded engine bays for easier reading while cranking or running the engine. A quick coupler on the hose means fast connect/disconnect without pressure loss, speeding up multi-cylinder checks.

• 25" flexible hose for better access and gauge placement
• Quick coupler for fast connection and release
• Reduced need to reach into confined engine compartments
• Flex lines included for both standard and extended reach scenarios

What protects the components and helps long-term serviceability?

Metal parts receive a corrosion-resistant nickel plating for durability in workshop conditions, and a blow-molded hard case keeps everything organized when not in use. The kit also includes a small repair parts pack so common wear items can be replaced without delay.

• Nickel-plated fittings resist corrosion
• Rugged blow-molded hard case with removable lid
• Included repair parts kit for on-the-spot fixes
• Components designed for frequent professional use

Who is this for: The OTC 5606 Compression Tester Kit suits professional technicians and serious DIYers who need a single, reusable solution for compression testing across many gasoline engines. If you service cars, motorcycles, marine engines, or small engines and want a durable gauge, wide adapter coverage, and a case that keeps tools ready between jobs, this kit is built for that workload.