JLG 1850SJ, Service And Maintenance Manual, Page: 257 / 712

SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS
3121619 5-5
Assembly And Torque Specifications
Prior to selecting the appropriate torque from the tables
within this section, it is necessary to properly identify the con-
nector being installed. Refer to the Figures and Tables in this
section.
GENERAL TUBE TYPE FITTING ASSEMBLY
INSTRUCTIONS
1. Take precautions to ensure that fittings and mating
components are not damaged during storage, handling
or assembly. Nicks and scratches in sealing surfaces can
create a path for leaks which could lead to component
contamination and/or failure.
2. When making a connection to tubing, compression or
flare, inspect the tube in the area of the fitting attach-
ment to ensure that the tube has not been damaged.
3. The assembly process is one of the leading causes for
contamination in air and hydraulic systems. Contamina-
tion can prevent proper tightening of fittings and adapt-
ers from occurring.
a. Avoid using dirty or oily rags when handling fittings.
b. If fittings are disassembled, they should be cleaned
and inspected for damage. Replace fittings as nec-
essary before re-installing.
c. Sealing compounds should be applied where speci-
fied; however, care should be taken not to introduce
sealant into the system.
d. Avoid applying sealant to the area of the threads
where the sealant will be forced into the system.
This is generally the first two threads of a fitting.
e. Sealant should only be applied to the male threads.
f. Straight thread fittings do not require sealants. O-
rings or washers are provided for sealing.
g. When replacing or installing an O-ring, care is to be
taken while transferring the O-ring over the threads
as it may become nicked or torn. When replacing an
O-ring on a fitting, the use of a thread protector is
recommended.
h. When installing fittings with O-rings, lubrication
shall be used to prevent scuffing or tearing of the O-
ring. See O-ring Installation (Replacement) in this
section.
4. Take care to identify the material of parts to apply the
correct torque values.
a. Verify the material designation in the table head-
ings.
b. If specifications are given only for steel fittings and
components, the values for alternate materials shall
be as follows: Aluminum and Brass- reduce steel val-
ues by 35%; Stainless Steel- Use the upper limit for
steel.
5. To achieve the specified torque, the torque wrench is to
be held perpendicular to the axis of rotation.
6. Refer to the appropriate section in this manual for more
specific instructions and procedures for each type of fit-
ting connection
Figure 5-11. Torque Wrench Angle