CYLINDER 5449412 - Caterpillar

Table 1
Sales Model     Closing Time     Opening Time    
VHC-30     1.9 seconds     3.2 seconds    
VHC-40     2 seconds     4.2 seconds    
VHC-50     2.6 seconds     3.8 seconds    
VHC-60     3.1 seconds     4.3 seconds    
If the cycle times are within the specifications, the jaw circuit is operating properly. If the cycle times are not within the specifications, check the oil flow and the oil pressure from the host machine. Refer to the Service Manual, "Host Machine Pressure and Flow - Test".
If an adjustment was made to the host machine, repeat the test. If an adjustment was not made or if the cycle times are not within the specification, check the speed control valve. Refer to Service Manual, "Speed Control Valve (Hydraulic Cylinder) - Test and Adjust".
If an adjustment was made to the speed control valve, repeat the test. If an adjustment was not made or if the cycle times are not within the specification, the seals within the cylinder may be worn. Check the cylinder seals for leakage. Refer to Service Manual, "Hydraulic Cylinder Leakage - Test".