{"product_id":"gnhydxfe-engine-cylinder-leak-down-tester-kit-tu-21-black-dual-gauge-manifold-regulator","title":"Gnhydxfe Engine Cylinder Leak Down Tester Kit TU-21 Black — Dual-Gauge Manifold \u0026 Regulator","description":"\u003cp\u003e\u003cstrong\u003eThe Gnhydxfe TU-21 Engine Cylinder Leak Down Tester Kit is a dual-gauge diagnostic tool that lets you pressurize a cylinder to measure leakage paths and estimate internal engine wear quickly and accurately.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf you service cars, trucks or motorcycles and need a straightforward way to check piston rings, valves, head gaskets or cracked cylinder walls, this TU-21 kit connects to a shop air source and shows both applied pressure and the percentage of leakage at once. The kit bundles a dual-gauge manifold, hoses, multiple adapters and threaded\/quick-connect fittings so you can access spark plug wells on most gasoline engines. Read on for how it works, what it includes, and when to reach for this tester.\u003c\/p\u003e\n\n\u003ch3\u003eHow does the TU-21 reveal where an engine is leaking?\u003c\/h3\u003e\n\n\u003cp\u003eThe tool pressurizes an individual cylinder through the spark plug hole and measures the pressure drop and leak rate simultaneously, making it easy to infer leak locations by listening or watching for pressure loss. Because you see both PSI and percent leakage, you can compare cylinders and pinpoint suspect areas for further inspection.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eDual gauge reads 0–100 psi and 0–100% leakage for quick diagnostics.\u003c\/li\u003e\n  \u003cli\u003ePressurizes via spark plug well using supplied adapters and hoses.\u003c\/li\u003e\n  \u003cli\u003eListen for air escaping at intake, exhaust, crankcase or coolant passages to locate faults.\u003c\/li\u003e\n  \u003cli\u003eUse pressure regulator to hold a steady test pressure from your air compressor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat parts are included and what fittings make it versatile?\u003c\/h3\u003e\n\n\u003cp\u003eThe TU-21 kit ships with a manifold assembly, an 18\" hose, a pressure regulator valve, two gauges, and a selection of adapters so you can reach most gasoline engine spark plug holes. It also includes straight and angled push-on connectors for convenience where threading a fitting is difficult.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eDouble gauge manifold with AR2000-style pressure regulator and American air plug.\u003c\/li\u003e\n  \u003cli\u003eOne rubber hose plus an extension hose and an M14 aluminum extension rod for deep wells.\u003c\/li\u003e\n  \u003cli\u003eTwo threaded adapters and two universal push-on connectors for wide engine compatibility.\u003c\/li\u003e\n  \u003cli\u003eAdapters cover spark plug wells up to 20 mm and work on bikes, cars, and light trucks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do you use it safely and accurately in the shop?\u003c\/h3\u003e\n\n\u003cp\u003eAlways follow basic safety: work on a cool engine, remove ignition and fuel sources, and rotate the engine to place the tested piston at near-TDC for a consistent baseline. Connect the manifold, set the compressor pressure with the regulator, pressurize the cylinder, then monitor leak percentage and listen for escaping air to determine the leak route.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eEnsure engine is off, cool, and ignition\/fuel disabled before testing.\u003c\/li\u003e\n  \u003cli\u003eRotate piston to near-top-dead-center to isolate the tested cylinder.\u003c\/li\u003e\n  \u003cli\u003eAdjust regulator to recommended test pressure and lock the valve knob for stable readings.\u003c\/li\u003e\n  \u003cli\u003eCompare readings across cylinders to spot abnormal leakage percentages.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat accuracy and engine types is the TU-21 best suited for?\u003c\/h3\u003e\n\n\u003cp\u003eThe gauges read 0–100 psi and 0–100% with stated accuracy near 0.5%, making the kit useful for routine shop checks and pre-purchase inspections on gasoline engines that accept spark plug style access. It's designed for petrol engines where spark plugs provide the test port and works with most passenger cars, light trucks and motorcycles.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003ePressure range: 0–100 psi (0–7 bar); leakage displayed 0–100%.\u003c\/li\u003e\n  \u003cli\u003eAccuracy around 0.5% for comparative diagnostics across cylinders.\u003c\/li\u003e\n  \u003cli\u003eSuitable for gasoline engines with spark plugs and wells up to 20 mm.\u003c\/li\u003e\n  \u003cli\u003eNot intended as a precision laboratory instrument but ideal for workshop troubleshooting.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The Gnhydxfe TU-21 kit is aimed at home mechanics, mobile technicians and professional shops that need a rugged, flexible leak-down tester for routine engine assessments. If you perform cylinder-by-cylinder diagnostics, pre-purchase inspections, or maintenance on petrol engines, this kit supplies the gauges, adapters and hoses to locate common internal leaks quickly and without specialized tooling.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use the TU-21 with any air compressor?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — as long as the compressor supplies stable pressure and can be adjusted to the tester's range; use a regulator and avoid exceeding 100 psi.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will the kit fit deep spark plug wells?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: It includes an M14 extension rod and extension hose to reach deeper wells, improving access on many engines.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Gnhydxfe","offers":[{"title":"Default Title","offer_id":48086157033630,"sku":"B0DF64D6B6","price":48.32,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/gnhydxfe-front-view.jpg?v=1785887345","url":"https:\/\/northtrailauto.ca\/products\/gnhydxfe-engine-cylinder-leak-down-tester-kit-tu-21-black-dual-gauge-manifold-regulator","provider":"North Trail Auto","version":"1.0","type":"link"}