ORIFICE 9W8394 - Caterpillar

Table 1
Tools Needed     Quantity    
4C-6585 Cylinder Pressure Indicator     1    An engine that runs roughly can have leaking valves and/or leaking piston rings. The compression of the individual cylinders can be compared in order to detect differences in the cylinders' compression. Perform either of the following procedures for each cylinder and then compare the results.
Install a 4C-6585 Cylinder Pressure Indicator onto a manual valve when the engine is stopped. Crank the engine without fuel and observe the gauge reading.
Alternatively, put the piston at the top center position on the compression stroke. The inlet valves and the exhaust valves will be fully closed. Connect a pressurized air line to the manual valve. Apply 500 kPa (73 psi) of air pressure to the cylinder and record the amount of time until the pressure is relieved.