JLG 4013PS Service Manual - Manual (Page 128)

Hydraulic System
8-18 3508PS, 3509PS, 3512PS, 3513PS, 4008PS, 4009PS, 4012PS, 4013PS, 4017PS, 40.8, 40.9
c. Cleaning and Drying
If contaminated hydraulic oil or foreign material is in the
tank, the tank can usually be cleaned.
To clean the hydraulic oil reservoir:
1. Have a dry chemical (Class B) fire extinguisher near
the work area.
2. Clean the hydraulic oil reservoir with a high-pressure
washer, or flush the tank with hot water for five
minutes and drain the water. Dispose of
contaminated water properly.
d. Inspection
Note: If a leak is suspected in the hydraulic oil reservoir,
contact JLG Service Department.
1. Inspect the hydraulic oil reservoir thoroughly for any
cracks, slices, leaks or other damage.
2. With the hydraulic oil reservoir removed from the
machine, plug all openings except one elbow fitting.
Install the elbow fitting, and apply approximately
0,06-0,10 bar (1-1.5 psi) of air pressure through the
elbow. Check the reservoir for leaks by applying a
soap solution to the exterior and look for bubbles to
appear at the cracked or damaged area.
e. Reservoir Installation
1. Lift the hydraulic oil reservoir into place and install
the six bolts, washers and nuts.
2. Uncap and connect the suction hose and return
hose. Tighten both clamps.
3. Uncap and connect the four small return hoses to
the fittings on the hydraulic oil reservoir.
4. Install the hydraulic oil level sight-glass using special
designed and drilled capscrews and gaskets.
5. Install hydraulic filter neck components and secure.
6. Fill the hydraulic oil reservoir according to
specifications. Refer to Section 2.4, “Fluids,
Lubricants and Capacities.”
7. Check the hydraulic oil reservoir for leaks.
8. Properly connect the battery.
9. Close and secure the engine cover.
10. Remove the Do Not Operate Tags from both the
ignition key switch and the steering wheel.
8.7 HYDRAULIC SYSTEM PUMP
8.7.1 Pump Description
For internal service instructions contact your local
authorized service distributor.
8.7.2 Pump Failure Analysis
The implement pump (1) is the “heart” of the hydraulic
system, and whenever there is a problem in the system,
the pump often is blamed. However, implement pump
failure is seldom due to failure of pump components.
Pump failure usually indicates another problem in the
hydraulic system.
According to pump manufacturer statistics, 90-95 percent
of pump failures are due to one or more of the following
causes:
• Aeration
• Cavitation
• Contamination
• Excessive Heat
• Over-Pressurization
• Improper oil
In the event of pump failure, investigate further to
determine the cause of the problem.
MZ1950
1