Jacobsen GA 24 Technical Manual Download

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MAINTENANCE 7

7.6

HYDRAULIC HOSES _______________________________________________________

1. Always disengage all drives, lower aerator head to

ground, stop engine and disconnect spark plug wire
before inspecting or disconnecting hydraulic lines or
hoses.

2. With engine stopped, move Tine Lever to RAISE

position for 10 seconds and LOWER position for 10
seconds to release system pressure.

3. Check visible hoses and tubes daily. Look for wet

hoses or oil spots. Replace worn or damaged hoses
and tubes before operating the machine.

4. The replacement tube or hoses must be routed in the

same path as the existing hose, do not move clamps,
brackets, and ties to a new location.

5. Thoroughly inspect all tubes, hoses, and connections

every 250 hours.

IMPORTANT:

The hydraulic system can be

permanently damaged if the oil becomes
contaminated.

Before disconnecting any hydraulic

component, clean the area around the fittings and the
hose ends to keep impurities out of the system.

a. Before disconnecting any hydraulic component, tag

or mark the location of each hose then clean the
area around the fittings.

b. As you disconnect the component, be prepared to

assemble plugs or caps to the hose ends and open
ports. This will keep impurities out of the hydraulic
system and also prevent oil spills.

Make sure “O” rings are clean and hose fittings are

properly seated before tightening.

d. Keep the hose from twisting. Twisted hoses can

cause couplers to loosen as the hose flexes during
operation resulting in oil leaks.

e. Kinked or twisted hoses can restrict the oil flow

causing the system to malfunction and the oil to
overheat and also lead to hose failure.

7.7

HYDRAULIC OIL___________________________________________________________

Refer to Section 9.2 for specific maintenance intervals.

Drain and replace the hydraulic oil after a major component
failure, or if you notice the presence of water or foam in the
oil, or a rancid odor (indicating excessive heat).

Always replace the hydraulic filter when changing oil.

To change hydraulic oil:

1. Clean the area around the oil cap to prevent impurities

from entering and contaminating the system.

a. Oil temperature should be at 60° to 90°F (16° -

32°C). Do not check oil level when oil is hot.

b. Check oil with aerator head in raised position.

c. The main oil tank should always be full.

2. Drain and replace the hydraulic oil every 250 hours or

after a major component failure, or if you notice the
presence of water, foam, or a rancid odor.

3. Remove drain plug from bottom of main tank and

loosen or remove dipstick/filler cap.

4. After oil has drained install drain plug and fill with

Jacobsen Hydraulic oil.

5. Purge air from system.

a. Operate lift / lower function for several minutes to

purge air out of the system and stabilize the oil
level.

b. Once the level has stabilized and the air is purged,

fill the tank to the FULL level.

WARNING

To prevent serious injury from hot, high pressure oil,
never use your hands to check for oil leaks, use paper or
cardboard.

Hydraulic fluid escaping under pressure can have
sufficient force to penetrate skin. If fluid is injected into
the skin it must be surgically removed within a few hours
by a doctor familiar with this form of injury or gangrene
may result.

DO NOT attempt to replace hydraulic hoses with aerator
head in raised position. Hoses are under extreme
pressure. Releasing pressure improperly could cause
aerator head to drop suddenly.