Hydraulic Product Safety Cheat Sheet

WARNING: Valve lever (spool) may “stick” (not center) under certain conditions, allowing the hydraulic equipment to continue to operate and could cause serious injury, death, or equipment failure.

January 6, 2024
hydraulic product safety cheat sheet

VALVE SAFETY: Read and follow instructions carefully. Failure to observe instructions and guidelines may cause serious injury, death, or equipment failure. A sticking valve (spool bind) may be caused by one or more of the following factors:

DIRTY OIL: Oil must be filtered to a minimum of 25 microns. Filters should be changed regularly – spin-on types after 50 hours of initial use and then after every two hundred fifty hours of use. Use of a condition indicator is recommended. Consult your tractor or implement the owner’s manual for filtration and changing recommendations for internal systems.

OIL REQUIREMENTS: Premium quality anti-wear type oil with a viscosity between 100 and 200 SSU at operating temperatures. Certain synthetic oils may cause spool seals to swell and the valve to stick. If in doubt, call CROSS Engineering.

IMPROPER HOOKUP OR MOUNTING: Always use the proper size fittings. Hook up “in” & “out” as noted on the valve body. Do not over-torque pipe fittings. (Use liquid pipe sealant only – cracked ports are not covered under warranty.) Mounting surfaces should be flat, and care should be taken when tightening mounting bolts. Over-tightened bolts can cause spool bind and casting breakage. Always use a power beyond the sleeve when hooking a valve in series. Consult your tractor or implement a manual to make sure you have the proper quick disconnect line connected to the inlet of the remote valve.

MISAPPLICATION: Always use the proper valve for the job. CONVERTA, CD, CS, or CA valves should never be used for metered heavy load lifting – loaders or similar applications. Use an open-center valve for open-center applications and a closed-center valve for closed applications. If in doubt, check with your tractor dealer. Contact CROSS if the valve allows the hydraulic equipment to creep excessively.

MAINTENANCE: Make sure all bolts are tightened and torqued to the recommended specification. Bent or broken parts should not be used. Replace immediately. Always use exact replacements. Always protect the valve spool from paint overspray. Faulty quick disconnects can cause high back pressures and sticking spools. Check quick disconnects periodically to make sure they are functioning properly. If the valve spool does not center or appears to stick, do not use it!


A relief or bypass in your hydraulic system is necessary to prevent the pump from breaking due to overpressurization. Use correct fittings and proper oil as noted in the technical service manual packed with each unit. Change oil as recommended by your implement or tractor manufacturer.


Check clevis clearances before, during, and after extending the cylinder and before using the cylinder under pressure to avoid possible injury or bent or broken rods caused by binding. (Bent or broken rods are not covered under warranty.) Never operate a cylinder above recommended pressures. Never use a cylinder as a safety device when transporting equipment.


If you observe a pinhole leak, discontinue the use of the component. If oil has penetrated your skin or contacted your eye, seek medical attention immediately!

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