Below are some common problems encountered when using manual or hydraulic fixtures, and some tips for solving those problems

Loss of parallelism of machined surfaces

• Check alignment of clamp pads over locators and work supports
• Locating surfaces may be damaged or need cleaning
• System pressure has excessively dropped or increased
• Sequence valves, pressure limiting and reducing valves are not functioning correctly
• Work supports are not extending to support part

Speed of clamping is extremely slow

• Check filter for trash or obstructions
• Contamination of hydraulic fluid may have restricted hydraulic components
• Flow rate of pump may be inadequate
• Air may need to be bled from system

Machined surface changes after fixture is unclamped

• Check clamp points to make sure they are properly opposed by rest points to prevent deflecting or stressing of parts
• Verify proper clamp forces are applied to the circuit per specifications recommended on the hydraulic schematic

Fixture will not achieve full system pressure while clamping or un-clamping

• Check to be sure that the system pressure gage is working. Replace gage if possible.
• Check fixture for external or internal leaks as well as possible leaks in the pump system feeding the fixture.
• If the fixture is equipped with an intensifier then verify that the intensifier is functioning correctly.
• If no leaks are found, check for valving problems such as a stuck check valve.