Hydraulic cylinder seal kits are used to seal the gap between different parts of the hydraulic cylinder. The function of hydraulic cylinder seal kits is to prevent oil leakage, to assure the working pressure of the hydraulic system, to maintain its power.
Boom Cylinder seal kit is, as the name suggests, fitted into the boom cylinder.
There are regularly three cylinders for the excavator, boom cylinder, arm cylinder, bucket cylinder.
Arm cylinder is the top one, and it's usually be called as top cylinder;
The bucket cylinder is the one that connects and controls the bucket.
Boom cylinder is the one (or the two) near the cabin. Usually, there is one piece boom cylinder for the small excavator under 10-tun; the bigger excavator's two pieces boom cylinders. But there is an exception too when the driver will remove one piece for a special purpose, say at some particular working place, it is convenient to work by one cylinder. Soft remind: all refit job should be operated by an experienced technician.

The seals in the cylinder seal kit are of two kinds seals.
One call dynamic seals; the other is static seals.

Dynamic seals are designed to be utilized in high pressure and even when rod and hydraulic cylinder seals are in reciprocal motion between the head and the connecting rod. They are to seal various parts in relative motion.

Static seals are the ones used in various locations that not in relative motion, as per the construction and look of the hydraulic cylinder. The primary area where these seals used are the connection rod and piston.

Every type of dynamic seals has its function.

Electric parts:

Steeper motor assy, solenoid valve, sensor, pressure switch, flameout solenoid, various starter switch, computer board, monitor, starting motor, alternator, generator.

Reduction gear parts:

Drive shaft, ring gear, sun gear, planet gear, pin, shaft, carrier, Carrier assy, hub, bearing, swing reduction, travel reduction, Casing, washer, oil seal, o-ring swing reduction, travel reduction, casing ,etc.

Engine parts:

Cylinder block, cylinder head, crankshaft, camshaft, liner kit, Liner, piston, piston ring, piston pin, rod &main bearing, bushing, Gasket kit, oil pump, water pump, feed pump, fan bland, plunger, Delivery valve, nozzle, connecting rod, turbocharger, oil cover, oil cooler, nozzle piping, thermostat, seat thermostat

Hydraulic parts:

Main pump, swing motor ,travel motor parts: piston ,block cylinder ,set plate, ball guide, shoe plate, swash plate, spring, washer, shaft, gear pump, pump seal kit, motor seal kit etc .

Undercarriage parts:

Track link assy, shoes track, front idler, track roller, carrier Roller sprocker, teeth, adapter, pin teeth, track bolt & spring, pin ,bushing, bucket.