Manitowoc Published 05-03-17, Control # 228-03 2-9
16000 SERVICE/MAINTENANCE MANUAL HYDRAULIC SYSTEM
Hydraulic Connections
Precautions to Observe During Maintenance and
Repair
Use the following precautions during maintenance and
repair:
⢠Make sure the fittings and o-rings being used are the
proper size and style.
⢠Flush the sealing surfaces with clean hydraulic oil to
remove any dirt.
⢠Carefully inspect the threads and sealing surfaces for
nicks, gouges, and other damage. Do not use damaged
parts. They will leak.
⢠Carefully inspect the o-rings for cuts and other damage.
Do not use damaged o-rings: they will leak.
⢠Always lubricate the o-rings when assembling onto
fittings.
⢠Be careful not to cut the o-rings when assembling them
to fittings. Use a thimble as shown in Figure 2-6
when
assembling o-ring over threads.
Pipe Thread Connection
1. Apply sealant (Loctite 92 or equivalent) to the male
threads, never to the female threads. Do not apply
sealant to the first two male threads.
2. Tighten fittings about 4-1/2 turns by hand and then 3
additional turns with a wrench.
Table 2-2
Pipe Thread Fitting Troubleshooting
O-Ring
Plastic or Metal
Thimble Covering Threads
FIGURE 2-6
S103
CAUTION
Hydraulic System Damage!
Do not use PTFE (teflon) tape to seal threads. Pieces of
tape will enter the hydraulic system and cause damage.
Causes Cures
Fitting loose. Tighten.
Fitting too tight causing thread
distortion.
Replace damaged parts.
Threads on fitting/port wrong size. Use proper size threads.
Threads dirty, galled or nicked. Clean or replace parts.
Straight thread used instead of
tapered thread.
Use proper type and
size thread.
Threads expanded from heat. Tighten when hot.
Fitting loosened by vibration. Retighten.