H0025 Overhaul of Compact S and Super S Series Hydraulic Cylinders Victor Hydraulics

This document is owned and distributed by Victor Hydraulics and we are publishing it in our Service Information on their behalf.

Overhaul of Compact S and Compact Super S Series Hydraulic Cylinders

• Cleanliness is critical, wash all parts and ensure all traces of solvent are removed
• Check seals, rod and bore of tube for any damage
• Piston will need to be removed to change the head seals
• Lightly coat all surfaces with oil. The head and tube contacting surfaces should be lightly greased
• It is essential that the piston to rod connection is correctly tightened during assembly or the the cylinder will fail

For Cap Screwed Models:

1. Remove cylinder head (gland) by turning anticlockwise (when looking at the cylinder from the rod end)
2. Do not over tighten head when reassembling (max approximately 200Nm)

For Blind Position Models:

1. The piston nylon lock ring must be replaced every time the piston is removed
2. Fit head on to the shaft first (wrap tape around the rod thread to avoid damaging head seals)
3. Lightly grease piston thread
4. Fit piston by hand and turn untill hand tight
5. Tighten to 800 to 1000 Nm
6. Wait for trapped air to escape (approximately 5 seconds) then tighten again to 800 to 1000 Nm

For 6" x 3" and 8' x 4" Compact Extra:

Torquing Prodcedure:

1. Torque to 50 Nm to establish an initial zero point
2. Torque to the angle specified from the zero point:
   • 70 - 73 degrees for 6" x 3"
   • 65 - 68 degrees for 8" x 4"
3. Un-torque
4. Torque to 50 Nm to establish new zero point
5. Retorque to the angle specified from the new zero point:
   • 70 - 73 degrees for 6" x 3"
   • 65 - 68 degrees for 8" x 4"

Pressure Testing Procedure:

1. Cycle in and out to remove air
2. Test at approximately 150 P.S.I for pressure drop and leaks
3. Test at approximately 3000 P.S.I for pressure drop and leaks
4. Test on the retract side with stroke restricting spacer placed between the head and the eye at 4800 P.S.I.

Complete seal kits, which include replacement cap screw, are available ex-stock from Steelbro NZ. Quote internal bore and shaft diameters when ordering.

The cap screwed piston design is the result of detailed research and stress analysis using advanced technology. The best fatigue life performance, and piston to shaft sealing, is obtained when the cap screw is correctly preloaded. A torque wrench is not adequate, as the preload produced on the threads will vary widely depending on lubricants or contaminants in the connection. Following these simple instructions will give the longest possible service life under arduous field conditions.