777 SERVICE MANUAL HYDRAULIC SYSTEM
Manitowoc Published 10-01-2012, Control # 045-08 2-11
2
Table 2-7
Split Flange Leakage
SAE Flare Connection
1. Tighten nut finger tight until sealing surfaces touch.
2. Mark a line (use felt pen or marker) on adapter and
extend it onto connector nut (Figure 2-11, View A).
3. Using wrenches, tighten connector nut the number of
flats shown in Table 2-8 (Figure 2-11, View B).
4. Misalignment of marks will show how much nut has
been tightened, and that it has been tightened.
Table 2-8
SAE 37° Flare Tightening
Table 2-9
SAE 37° Flare Leakage
Causes Cures
Flanges not tight.
Tighten bolts evenly to
proper torque.
Flanges tightened unevenly
causing extrusion of O-ring.
Replace O-rings. Tighten
bolts evenly to proper
torque.
O-ring cut. Replace.
O-ring wrong size. Replace with proper size.
Sealing surfaces not
smooth; scratched or
gouged.
Repair if possible or
replace parts.
Sealing surfaces dirty. Clean.
Flanges keep getting loose
in service.
Use SAE grade 5 bolts or
better. Retighten bolts after
system is hot.
Connector Nut Size
inch across flats
Fitting
Size
Adapter Flats
to Rotate
9/16 -04 2-1/2
5/8 -05 2-1/2
11/16 -06 2
7/8 -08 2
1 -10 1-1/2 – 2
1-1/4 -12 1
1-1/2 -16 3/4 – 1
2 -20 3/4 – 1
2-1/4 -24 1/2 – 3/4
Causes Cures
Joint loose. Tighten properly.
Sealing surfaces dirty. Clean.
Sealing surfaces not smooth;
scratched or gouged.
Replace faulty parts.
Sealing surfaces cracked. Replace faulty parts.
SAE 45° parts used with SAE
37° parts.
Use only SAE 37° parts.
Turn connector nut required
number of flats (Table 2-8)
S108
FIGURE 2-11
Connector
Nut
Adapter
Line
View A
View B