KIT-SEAL 3829255 - Caterpillar

Table 1
Tools Needed    
Part Number     Part Name     Qty    
9U-6274     Compression Test Tool Gp     1    The following conditions can affect the results of the cylinder compression test:
Battery
Condition of the starting motor
Ambient conditions
Quality of the compression gauge
Illustration 1 g02700596
Checking compression of engine
Remove the injector lines and the injection nozzles.
Set the fuel injection pump to zero delivery (disconnect the fuel cutoff solenoid)
Turn the engine.
Install a compression gauge on the cylinder to be measured.
Use the starter to turn the engine Read the pressure on the gauge.
If the measured value is at the limit or below the limit, overhaul the engine.
Table 2
    Standard at Assembly     Repair Limit    
Compression Pressure (1)    
34.3 1 bar (497 15 psi)    
27.5 1 bar (399 15 psi)    
( 1 ) The compression pressure is taken at 250 rpm.
Be sure to measure the compression on all of the cylinders. If all of the cylinders are not checked an improper diagnosis may result. The compression pressure will vary with the change in engine rpm. It is necessary to keep the engine rpm constant for all cylinders when you are taking a compression reading.