FASTENER GP-FRONT COVER 2501120 - Caterpillar

Boom Cylinder Features
Illustration 1 g03613296
Hydraulic cylinder (typical example) (1) Boom hydraulic cylinder (2) Control valveThe hydraulic boom cylinder has the following features:
Auto and manual grease ports on each end
Heavy-duty manganese bronze bushings
Grease wiper seals on pins to retain grease and keep out contamination
Induction hardened, chrome rod and chrome barrel
Bolt on gland cap
Heavy duty high-pressure oil sealing system
Safety load holding valve on bore side to prevent cylinder retract in the event of hose rupture
Pressure equalizing lines used for even loading
Relief setting 5300 psi
Rod side pilot signal release oil from bore to tank
Air release valves to release air from long pilot linesPiston Seals
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(1) Wear bands (2) Piston seal (OD) (2a) Plastic anti-extrusion ring (2b) Filled PTFE cap (2c) Elastomeric energizer (3) Piston seal (ID)Wear bands (1) prevent the piston from touching the ID of the barrel.Piston seal (OD) (2) capped t-seal blocks oil from by-passing through the piston between the barrel ID and the piston OD.Piston seal (ID) (3) o-ring and backups blocks oil from by-passing through the piston between piston ID and the rod OD.Head Seals
Illustration 3 g03342759
(1) Wear bands (2) Head seal (3) Buffer seal (4) Rod seal (5) WiperWear bands (1) prevent the rod from touching the ID of the gland head.Head seal (2) o-ring and backup blocks oil from bypassing through the gland head between the gland head and barrel.Buffer seal (3) is the firs seal that sees pressure. The purpose is to reduce pressure spikes on the rod seal and increasing the life expectancy.Rod seal (4) deep z seal blocks oil from bypassing externally through the gland head. The seal also blocks external liquid from entering the cylinder.Wiper (5) excluder has a lip seal that is pointed outward to wipe off debris of the rod. The purpose is to prevent contamination from entering the cylinder.