III-100
Note:
See the Thermostat section in
Chapter 10
. Fan clutch, ra-
diator shutter, condenser, compressor, and the newer air
and water valve control systems are covered in
Chapter
10
.
Review of Frequent Problem Areas
In HVAC systems a limited number of things can go wrong. Moving parts of the com-
pressor, clutch, and expansion valve or refrigerant metering device can malfunction or
break down from metal fatigue, contamination, abnormal pressure or lack of lubrica-
tion. Electrical connections may corrode, become disconnected or break. Fuses blow
from shorts or overload. Belts slip or break.
Vibration from the engine or road surface can work bolts and air or vacuum lines
loose, or rub and break or wear parts out. Motors may burn out. The inside of the
system can become contaminated from moisture, air or desiccant material breakdown.
Refrigerant may leak out of the system quickly or very slowly. Moisture in the system
can combine with refrigerant to form acid and attack (corrode) metal parts from the
inside. Moisture and refrigeration oil can combine to form sludge that may block re-
frigerant flow.
The following problems are discussed in more detail in this section:
1.
Belts and Compressor Clutch
2.
Condenser
3.
Refrigerant Lines, Hoses, and Fittings
4.
Refrigerant Metering Valves
5.
Other Problems
1. Belts and Compressor Clutch
Let
·
s review problem areas listed at the beginning of
Chapter 7
. The most fre-
quent repairs are replacing belts and servicing or replacing the compressor or
clutch. Heavy duty vehicle operation puts a lot of stress on these parts. There are
several main reasons.
There is often continuous operation for long periods of time. There may be
frequent sudden RPM variations when shifting gears up or down. For this reason
the AC clutches used in heavy duty systems usually have double row ball bear-
ings. Vibration and road shock contribute to loose or broken mounting brackets,
electrical connections and fittings. Belts, bearings and compressor reed valves
wear out.
Various compressor clutch cutout switches are used because the AC designers
know about compressor operating conditions. System leaks, high operating pres-
sures, malfunctioning engine cooling system components—all cause compressor
problems and failures. When refrigerant and refrigeration oil leaks out of a sys-
tem or there is contamination blocking oil flow, the compressor will be starved
for oil and seize.
Review of Frequent Problem Areas
Summary of Contents for TL150
Page 1: ...TL150 Track Loader BOOK No CT7E901 WORKSHOP MANUAL Serial No 21500004...
Page 4: ...0 4...
Page 5: ...I 1 I GENERAL...
Page 18: ...I 14 GENERAL...
Page 19: ...II 1 II SPECIFICATIONS...
Page 44: ...III 1 III MACHINE CONFIGURATION...
Page 94: ...III 51 MACHINE CONFIGURATION ELECTRICAL SYSTEM ELECTRICAL SYSTEM ELECTRICAL WIRING DIAGRAM...
Page 122: ...III 79...
Page 146: ...MACHINE CONFIGURATION III 103...
Page 147: ...IV 1 IV HYDRAULIC UNITS...
Page 152: ...IV 6 HYDRAULIC UNITS HST PUMP 1 Plug 2 Plug 3 Plug 4 Screw 5 Seal Nut 6 Plug Pump Assembly 4 4...
Page 189: ...IV 43 HYDRAULIC UNITS GEAR PUMP INSPECTION AND ADJUSTMENT IV 36 38 TROUBLESHOOTING IV 39...
Page 230: ...IV 84 HYDRAULIC UNITS PILOT VALVE INSPECTION AND ADJUSTMENT IV 79 TROUBLESHOOTING IV 80...
Page 261: ...IV 115 HYDRAULIC UNITS TRAVEL MOTOR DISASSEMBLY AND ASSEMBLY Special tools...
Page 263: ...IV 117 HYDRAULIC UNITS TRAVEL MOTOR...
Page 282: ...IV 136 HYDRAULIC UNITS TRAVEL MOTOR...
Page 283: ...V 1 V TROUBLESHOOTING...
