
78
SERVICE MANUAL FOR SGR19 & SGR17
List of criteria for judging oil deterioration (Draw some oil out of the HST case into a test tube and
compare the sample with fresh oil.)
Appearance
Smell
Condition
Countermeasure
Transparent and with no discolouration
Normal
Good
Keep on using as it is
Transparent but with small back dots
Normal
Mixed with foreign matter
Keep on using after filtering
Milky white
Normal
Mixed with water
Replace with new oil
Blackened
Bad
Oxided and deteriorated
Replace with new oil
4.11. TROUBLESHOOTING
When the HST unit is defective, it should be replaced with a new one as a rule. The following table will
assist you in understanding the HST system.
Trouble
Presumable cause
Countermeasure
The output shaft does not turn
1. Improper set pressure of relief
Measure the pressure of low pressure
even when the control lever is
valve in low pressure side
circuit and replace defective parts
shifted either to
α
or
β
side.
(Decreased pressure)
if necessary.
2. Improper set pressure of relief
Measure the pressure of high pressure
valve in high pressure side
circuit and replace defective parts
(Decreased pressure)
if necessary.
3. Broken charge pump (Decreased
Replace defective parts with new ones.
charge flow)
4. Air is trapped within the HST
Check suction piping of the charge
system.
pump and oil level in the tank. (After
correction, bleed the HST system of
air.)
5. Erratic operation of the HST unit
Wash the hydraulic circuit of the ma-
due to defective inner parts or
chine thoroughly, repair the coupling
defective coupling of input or
and replace the HST unit assembly
output shaft
with a new one.
The output shaft does not stop
1. Erratic operation of the check
Disassemble, wash it clean, and then
turning even when the control
valve (Clogged choke)
reassemble.
lever is shifted to the neutral
position.
2. Defective check valve seat
Replace a defective seat with a new
one.
Low revolving speed of output
1. Highly pressurized oil is leaking
Wash the hydraulic circuit of the ma-
shaft of the HST
through worn frictioning parts
chine thoroughly, replace the HST unit
of the pump or motor of the HST.
assembly with a new one.
2. Air is trapped within the HST
Check suction piping of the charge
system
pump and oil level in the tank. (After
correction, bleed the HST system of
air.)
3. Decreased circuit flow caused
Clean a clogged filter or strainer.
by a clogged filter or strainer
Содержание SCM49
Страница 1: ...S E R V I C E M A N U A L I S E K I L A W N M O W E R S LAWN MOWERS MOWER DECKS SCM48 SCM54 ...
Страница 7: ...7 CHAPTER 1 INTRODUCTION 3 EXTERIOR VIEW AND DIMENSIONS 1935 mm 1965 mm 1100 mm 1265 mm ...
Страница 36: ...36 SERVICE MANUAL FOR SGR19 SGR17 Fig 3 55 III 3 CYLINDER BLOCK 1 EXPLODED VIEWS ...
Страница 97: ...97 CHAPTER 8 MANUAL STEERING SYSTEM CHAPTER 8 MANUAL STEERING SYSTEM 1 CONSTRUCTION Fig 8 1 2 GEAR BOX Fig 8 2 ...