Manitowoc 999 Service And Maintenance Manual

Reference Only
Manitowoc Published 05-16-17, Control # 233-03 2-7
999 SERVICE/MAINTENANCE MANUAL HYDRAULIC SYSTEM
2
10. Replace all filter elements (1, 14 and 17).
11. Fully close drain valve (18) and remove rubber hose.
12. Fill hydraulic tank to proper full (cold) level on tank sight
gauge (3). Use proper hydraulic oil (see Lubrication
Guide supplied with crane). Filter oil with 10-micron
element as oil is added to tank.
13. Make sure shutoff valves (15 and 16) are fully opened.
14. At engine, check that engine clutch is engaged.
15. Start and run engine at low idle for 10 to 15 minutes to fill
all lines with oil and to bleed any air from system.
16. Stop engine and fill hydraulic tank to proper level as
indicated on sight gauge.
NOTE: If hydraulic system is extremely dirty (gum or
lacquer formation on parts indicated by erratic,
jerky, or sluggish operation) repeat Changing Oil
procedure after 48 hours of operation.
Tightening Hydraulic Connections
• Make sure fittings and O-rings being used are proper
size and style.
• Flush sealing surfaces with clean hydraulic oil to remove
any dirt.
• Carefully inspect threads and sealing surfaces for nicks,
gouges, and other damage. Do not use damaged parts;
they will leak.
• Carefully inspect O-rings for cuts and other damage. Do
not use damaged O-rings; they will leak.
• Always lubricate O-rings when assembling them to
fittings.
• Be careful not to cut O-rings when assembling them to
fittings. Use thimble as shown in Figure 2-2
when
assembling O-ring over threads.
Pipe Thread Connection
1. Apply sealant (Loctite
®
92 or equivalent) to male
threads, never to female threads. Do not apply sealant
to 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 Leakages
CAUTION
Hydraulic System Damage!
Do not use PTFE (Teflon
®
) tape to seal threads. Pieces of
tape will enter hydraulic system and cause damage.
Causes Cures
Fitting loose. Tighten.
Fitting too tight causing thread
distortion.
Replace damaged parts.
Threads on fitting or in 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.
Female threads expanded from
heat.
Tighten when hot.
Fitting loosened by vibration. Re-tighten.
O-Ring
Plastic or Metal
Thimble Covering Threads
FIGURE 2-2
S103

Manitowoc 999 Specifications

General

Brand	Manitowoc
Model	999
Category	Construction Equipment
Language	English