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Lutifix Tu-21 4Pcs Cylinder Leak Tester Compression Test Kit Cylinder Petrol Engine Compression Leakage Leakdown Detect

Lutifix Tu-21 4Pcs Cylinder Leak Tester Compression Test Kit Cylinder Petrol Engine Compression Leakage Leakdown Detect

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Tu-21 Engine Cylinder Leak Tester Leakage Detector

  • This tester can readily locate a blown head gasket that a Compression Test will completely miss.

  • Their Cylinder Leakage Tester is reasonably well made and reasonably accurate tools for the DIY automotive mechanic.

  • This tester has two different connection, Input air and Output air to cylinder. The Input connects to your 90-100psi shop air compressor with NPR Quick connect couplers and the Output connects to the cylinder under test a special Test Hose. The test hose has 14mm male threads to screw into the spark plug hole (hand tighten only) and a NPR Quick connector to connect to the Tester's Output port.

  • Tester checks the amount of leakage in an engine cylinder & helps determine the source. Best used when comparing a suspect cylinder to a known good cylinder on same engine. Ideal for testing trucks & late model cars where clearance is minimal. Equipped with 2-1/2\" input pressure gauge for proper leakage test setup and accurate results.

  • Package Size (LWH): 37cm x 27cm x 8cm/14.56" x 10.62" x 3.14"

  • Designed to detect a variety of common engine faults including: Worn piston rings, worn valves, cracks in cylinder walls and blown head gaskets. Available with either single gauge or twin gauge manifold. Gauges show % of cylinder leakage or cylinder leakage and cylinder pressure.

  • Suitable for use on any petrol engine with 10, 12 or 14mm spark plugs.

  • TU-21 Cylinder Leak Detector

  • Pinpoint the source of compression problems by doing cylinder leak-down tests Works with domestic and import engines Input and leakage gauges with rubberized housing.

  • Air pressure: 0-10 BAR, 0-140 PSI

  • Measures leak percentage from 0-100% 1/8\" NPT manifold ports

  • Package Content: 1 x Cylinder Leak Detector Set.
    Air Supply

    The recommended hook-up is shown below

    1. ensure that the air valve regulator is in the "off" position before connecting to the air supply

    2. will require an air pressure of 45 to 100psi

    3. WARNING! ensure the air supply is clean and does not exceed the pressure quoted. too high an air pressure and/or unclean air will shorten the life of the tester due to excessive wear and may be dangerous, causing damage and/or personal injury.

    4. drain the compressor air tank daily. water in the air line will damage the tester.

    5. clean compressor air inlet filter weekly.

    6. line pressure should be increased to compensate for unusually long ari hose (over 8 meters). the minimum bore for hose and fitting is 1/4"

    7. keep hose away from heat, oil and sharp edges. Check hos es for wear and make certain that all connections are secure.


Low compression reading on some cylinders

1. Use oil in cylinder to see if rings are worn

2. if compression increases, rings and/or cylinder wall are worn

3. if compression does not rise, do a cylinder leakage test to determine source of problem

high relative compression readings and relatively equal cylinder readings.

but, if excessive exhaust emissions, lack of power, poor performance, or poor fuel consumption do a cylinder leakage test to determine source of problem.

lower relative compression readings. one or more cylinders lower than others

do a cylinder leakge test to determine source of problem.

Cylinder Leak Tester


Cylinder air leakage measuring instrument is suitable for detecting whether the air-tightness of automobile engine cylinders is within the allowable air leakage range; it can further determine the air leakage location and cause from the analysis of the failure phenomenon, so as to take measures to eliminate the failure.


The inspection principle is to inject a certain amount of compressed air into the cylinder when the engine is static and the piston is at the top dead center position of the stroke. The time it takes for the air pressure to to a specified value reflects the size of the air leak. The shorter the time, the larger the air leakage. 3 On the contrary, the smaller the air leakage. If the constant pressure air is continuously supplied, the main parts causing the air leakage can be judged, so that the engine can be maintained in a targeted manner.

•Instrument structure:

The instrument consists of a pressure regulator, an intake pressure gauge, a measuring pressure gauge, an air duct, a quick-change connector, etc.

the main technical parameters:

Pressure measurement range: 0—1 MPa

Inlet pressure range: 0-l.6 MPa

Working air pressure: 0.6—0.8 MPa

•How to use:

1. Remove the spark plugs of the engine, use the handle to turn the crankshaft to make the piston at the top dead center, engage the direct gear, and tighten the parking brake to prevent the compressed air from pushing the piston to move during the test.

2. Screw the air supply connector on the first cylinder at the compression top dead center, connect the quick-change connector end of the air duct to the output end of the measuring instrument, and at the same time, connect the air compressor to the input end of the test instrument . Close the pressure regulating valve of the instrument (pull out the pressure regulator knob when in use).

3. Start the air compressor to inflate, and close it when the charging reaches 0.8MPa, prepare the stopwatch, quickly start the pressure regulating valve, press the stopwatch at the same time, record the pressure holding time, observe the change of the pressure gauge, when the gauge pressure s When it reaches 0.4 MPa, press the stopwatch to record the time it takes for the gauge pressure to from 0.8 MPa to 0.4 MPa. Use this length of time to compare similar machines to diagnose the degree of damage to the cylinder air leakage. The longer the maintenance time, The better the air-tightness of the cylinder; if the pressure holding time is very short, usually less than 10 seconds, it indicates that the air redness is serious and the air leakage must be repaired. In order to facilitate the test, the test sequence of each cylinder is carried out according to the firing order of the cylinders. One cylinder can be tested for every half revolution (180°) of the crankshaft.

4. Judgment of leaking location:

Simultaneously actuate the air compressor to deliver air to the cylinder at the top dead center. Use the pressure regulating valve to control the pressure at 0.6MP3. Listen carefully to the sound of air leakage to determine where the cylinder is leaking. If you hear the sound of air leakage at the intake manifold, it means that the intake valve is not sealed; if you hear the sound of air leakage at the muffler port of the exhaust pipe, it means the exhaust valve is not sealed; if you hear it at the oil filling port, Generally, there is a sound of air leakage, and a slight small sound is normal; if you hear a loud sound and feel that there is air flow, it is a serious air leakage, indicating that the cylinder-piston pair is not sealed: If you see air bubbles at the radiator filling place Emerging from the water indicates that the cylinder head gasket is burnt out, causing the cylinder and the water jacket to pass through; if you hear the sound of air leakage at the spark plug port adjacent to the cylinder, it indicates that the cylinder head gasket is burned out between the two cylinders and a cylinder flush occurs.


Condition: 100% Brand New
Material:  Rubber, hardware
Color: Red (Shown as picture)
Size: Shown as picture
S-park plug adapter: 12mm, 14mm
Gauge scale: 0-100PSI
Quantity: 4Pcs
Package Weight: Approx. 1836g


Lutifix Tu-21 4Pcs Cylinder Leak Tester Compression Test Kit Cylinder Petrol Engine Compression Leakage Leakdown Detect

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