Cylinder Leak Down Tester,Compression Test kit -Engine Cylinder Dual Gauge Leakdown Tester kit Diagnostics Tool.

Product Information

Generally, a typical automotive engine pressurized to more than 30-40 psi must be locked or it will rotate under test pressure.

A leak-down tester is a measuring instrument used to determine the condition of internal combustion engines by introducing compressed air into the cylinder and measuring the rate at which it leaks out.Designed to detect a variety of common engine faults such as worn piston rings, cylinder head cracks, worn valves and blown head gaskets. There is less tendency to rotate when the piston is at top dead center, especially with small bore engines. Most instruments use 100 psi (690 kPa) as the input pressure simply because ordinary 100psi gauges can be used which corresponds to 100% but there is no necessity for that pressure beyond that. Some poorly designed units do not include a restriction orifice at all, relying on the internal restriction of the regulator, and give much less accurate results.

I used it a few times, replaced the guages with ones I had, tried it again, then tossed it in the trash! This kit is rated to handle a maximum of 300 PSI, and is suitable for all gas motors in automobiles, motorcycles, and even marine equipment. Re zero the gauge between each test, do multiple tests on each cylinder, get the feel of how this stuff is working. Testing is done on an engine which is not running, and normally with the tested cylinder at top dead center on compression, although testing can be done at other points in the compression and power stroke. There is no standard regarding the size of the restriction orifice for non-aviation use and that is what leads to differences in readings between leak-down testers generally available from different manufacturers.If there is, the affected cylinder(s) will show compression numbers significantly lower than the others. One test result where a compression tester can be as good as a leak-down test: If two cylinders side-by-side have lower compression than the rest, the most likely cause is a blown head gasket between the cylinders. A leak down tester sized for automotive engines (usually 600-700 cc cylinders) will NOT work properly for a much larger or much smaller cylinder sizes.

At low and modest leakage percentages, there is little or no difference between single and dual gauges.The readings are taken from the second gauge, the first gauge which you use for zeroing will be lower as well. There is commonly a tiny level outside the switch case which operates the blow off for the compressor. The input pressure is set for 80 psi (550 kPa), and 60 psi (410 kPa) minimum cylinder pressure is the accepted standard. If the timing mark is off more than 1/2 degree a free engine (no plugs and not in gear) will spin 180degrees when 100PSI is applied to the cylinder at TDC compression. He delights in parsing complex subjects for anyone who will listen -- because teaching is the best way to ensure that you understand things yourself.

A compression tester is a stand-alone tool that relies on the engine's compression to build pressure in the cylinder. This means that a leak-down tester can be used to show when an engine is in need of a rebuild due to wear. To use a leak-down tester, you remove the spark plugs as above and rotate the engine until the piston is at top dead center for the cylinder you are testing.There will be a pressure drop across the orifice and another across any points of leakage in the engine. On top of that, racing engines are usually modified to have higher compression anyway, so you can't rely on a factory manual for the answer. You might think of a compression test like a doctor taking your pulse, and a leak-down test like a full EKG stress test.