Allmand — Cylinder Assembly
Repair & overhaul · Hydraulic cylinder
From a Allmand operator's manual — check it applies to your exact model before use.
Before you start
- Be careful not to damage seals and o-rings on edges or holes in cylinder tube.
- Inspect and remove burrs and sharp edges before reassembly.
Procedure
- Place rod seal (3) into groove inside cylinder head; lips of seal must face inward.
- Install wiper seal (2) with lip facing out and flush with top of cylinder head.
- Install wear ring (7) inside other end of head.
- Place o-ring (5) with back-up washer (4) in groove on outside of head; washer on rod side.
- Lubricate wiper seal (2) and rod seal (3); slide head carefully onto shaft.
- Place o-ring (8), piston seal (10) and piston wear ring (11) in grooves on outside of piston.
- Slide piston onto threaded end of shaft and install lock nut (12).
- Lubricate seals; slide piston and head into cylinder tube and insert wire retaining ring (14).
Specs & values
- Tighten lock nut (12) to 300 ft. lbs. on swing, bucket and stabilizer cylinders
- Tighten lock nut (12) to 375 ft. lbs. on lift and dipperstick cylinders
- Place seal (3) and piston seal (10) in 120°F water to warm seal
Source: Allmand operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.