Faulty operation of the differential valve may be caused by defective valve seals, the spring, or the diaphragm. The diaphragm and the O-Ring valve seat are the only parts that should require replacement in normal service. It is unnecessary to remove the valve from the line for disassembly.
Follow the steps below to disassemble the differential valve:
Step 1Remove connecting tube between differential valve and vapor eliminator cover.
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Step 2Unscrew the union nut and remove the spring case, limit stop, and spring from the body. |
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Step 3Remove the diaphragm and piston assembly. |
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Step 4The diaphragm can be inspected by unscrewing the nut and removing the diaphragm head.
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Step 5Inspect the diaphragm for cuts, tears, or pinhole leaks. Replace if defective. CAUTION: Do not over tighten diaphragm retaining nut. Torque the diaphragm retaining nut to 18-20 inch-lbs.
Check the o-ring and replace if necessary.
Reinstall piston assembly into body, insert spring, limit stop, spring case and union nut. Then, reassemble the connecting tube. |
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