Checking For Loss Of Pressure

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The check for loss of pressure can be used to assess the mechanical condition of a combustion engine.
A pressure loss test is more meaningful than the compression pressure check.
The percentage leakage quantity can be used to determine whether the leaks in the combustion chamber in question are so large that the combustion chamber must be repaired.
The worn components (e.g. piston rings) can be identified by the compressed air that is escaping.

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CAUTION: Read the work steps and tips in the attached operating instructions before starting the pressure loss test. The device described here is used as an example for all suitable pressure loss testers. Details of calibration and use can be found in the relevant operating instructions.

VAS 522 001 - Pressure loss tester must be ready.
Screw the test hose into the spark plug thread of cylinder 1 by hand and tighten hand-tight.

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Test hose
VAS 522 001 - Pressure loss tester must be connected to the compressed air system.
Insert front test nozzle into VAS 522 001 - pressure loss tester .

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Test nozzle in pressure loss tester
Adjust the scale. Adjusting the scale

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Adjusting the scale
1. 5.1 Turn the adjusting wheel for as long as required until the pointer on the scale is at the marking cal. or 23% in order to set the same pressure in both test chambers of the pressure lost tester.
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The piston must be exactly at the upper return point when checking pressure loss. Do not touch any components of the belt drive and do not put any tools on the crankshaft pulley while performing the check.
Check pressure loss at cylinder 1. Pressure loss test

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Pressure loss test
1. 6.1 Remove test nozzle from VAS 522 001 - pressure loss tester and check that the pointer falls back.
2. 6.2 Connect test hose to VAS 522 001 - pressure loss tester . The value that is displayed should not be greater than 25%. If the pressure loss is greater, it is safe to assume that the engine needs an overhaul.
Interrupt the compressed air supply and unscrew the test hose.
Check the next cylinder by turning the crankshaft through another 180° and check the pressure loss of the next cylinder in the firing order following the instructions provided.
Firing order: 1 - 3 - 4 - 2