I found need to replace the Hydraulic Relief Valve on my TO30, again. After activating the Relief Valve under heavy load, the lift began to rapidly leak down and required the valve replacement. This condition occurred after no loads heavy enough to activate the valve had been applied for about a year. The fluid used in this mild climate is NAPA SAE 90, API GL-1 and has been in about one year.
I’ve replaced the valve and all’s fine. I noticed the poppet stem of the old valve protruded .022†beyond the surface of the compression spring nut whereas the poppet stem of the new valve was flush with the compression spring nuts surface. I suspected foreign material between the poppet valve and its seat.
Before disassembling the valve for inspection, I made a test fixture using a grease-gun head to pressurize the valve. The valve leaked at less than 100 psi. I disassembled the valve and found it clean, except for oil. I cleaned out the oil and reassembled the valve using the same compression spring nut position as before; this time the poppet stem was flush with the compression spring nut’s surface. Retesting, it held pressure to the rated 2000 psi. (See picture).
I suspect the valve became misaligned with the seat and the stem was binding in the spring compression nut. Have others had this problem? Any comments?
The last Relief Valve replacement was with Part #: 181087M1 that included the statement “may look different than pictured, but will fit and work the same.†I’m concerned the valve may be of poor quality.
I’ve replaced the valve and all’s fine. I noticed the poppet stem of the old valve protruded .022†beyond the surface of the compression spring nut whereas the poppet stem of the new valve was flush with the compression spring nuts surface. I suspected foreign material between the poppet valve and its seat.
Before disassembling the valve for inspection, I made a test fixture using a grease-gun head to pressurize the valve. The valve leaked at less than 100 psi. I disassembled the valve and found it clean, except for oil. I cleaned out the oil and reassembled the valve using the same compression spring nut position as before; this time the poppet stem was flush with the compression spring nut’s surface. Retesting, it held pressure to the rated 2000 psi. (See picture).
I suspect the valve became misaligned with the seat and the stem was binding in the spring compression nut. Have others had this problem? Any comments?
The last Relief Valve replacement was with Part #: 181087M1 that included the statement “may look different than pictured, but will fit and work the same.†I’m concerned the valve may be of poor quality.