TM 5-3805-260-24
PROBLEM: Percent of flow loss for Tests 4 through
7 is more than the percent shown on Chart A.
PROBABLE REASON:
A. Bad pump.
B. Leakage in the relief valve.
C. Wear or damage in the valve body and/or
valve spools.
RECOMMENDATION FOR ACTION:
A. Do the Scraper Pump Tests, Chart C1.
B. If the extra percent of flow loss is not caused
by a bad pump, problem is in the control valves or relief
valve.
PROBLEM: Percent of flow loss for Tests 4 and/or 5
is more than 15%; for Tests 6 and 7,
percent of flow loss is less than the
percent shown in Chart A.
PROBABLE REASON:
A. Leakage in the ejector cylinder piston seals.
B. Leakage in the ejector check valve.
C. Leakage in the floor cylinder.
D. Leakage in the floor check valve.
E. Wear or damage in the control valve body
and/or valve spool.
RECOMMENDATION FOR ACTION:
Do the Blocked Circuit Tests 34 and 35 for the
ejector circuit. If leakage is still too high, the problem is
in the ejector control valve. Inspect its components.
PROBLEM: Percent of flow loss for Tests 6 and 7 is
more than the percent shown in Chart A; for Tests 4 and
5, it is less than the percent shown in Chart A.
PROBABLE REASON:
A. Leakage in one or both of the piston seals for
the bowl cylinders.
B. Wear or damage in the valve body or spool in
the bowl circuit.
RECOMMENDATION FOR ACTION:
Do the Blocked Circuit Tests 36 and 37 for the
bowl circuit. If leakage is still too high, the problem is in
the bowl control valve. Inspect its components.
PROBLEM: Down drift of bowl in Test 21 is more in
the RAISE position than in the HOLD position.
PROBABLE REASON:
Leakage in the scraper control valve.
RECOMMENDATION FOR ACTION:
Do Blocked Circuit Test 36 for the bowl circuit. If
leakage rate for the control valve is too high, check the
bowl control valve.
PROBLEM: Down drift of bowl in Test 21 is the same
in the RAISE position as in the HOLD
position but more than the amount
permitted in the Service Manual for the
machine under test.
PROBABLE REASON:
A. Leakage in the carry check valves.
B. Leakage in the pistons seals in the bowl
cylinders.
C. Leakage in the scraper control valve.
RECOMMENDATION FOR ACTION:
Do Blocked Circuit Tests 36 and 37 for bowl
circuit. If leakage is not found in control valve, do
Blocked Components Tests 45 and 46. If leakage is still
not found in bowl cylinders, the problem is in the carry
check valves. Remove and inspect them for damage or
wear. Replace parts as needed.
PROBLEM: Percent of flow loss for Test 17 is more
than the percent shown in Chart B; for
Tests 15 and 16, it is less than or the
same as the percent shown on Chart B.
PROBABLE REASON:
A. Bad small pump, Chart C3.
B. Excessive leakage in speed control valve.
RECOMMENDATION FOR ACTION:
Do the Pump Test, Chart C3. If the larger
amount of flow loss is not caused by the small pump, do
the Speed Control Valve Leakage Test 55.
PROBLEM: Setting for the main relief valve is higher
or lower than given in Test 10. Percent
of flow loss for Tests 15 through 17 is
20% to 50%.
PROBABLE REASON:
Setting for main relief is not correct and leakage
is too high.
RECOMMENDATION FOR ACTION:
Make adjustments to the main relief valve to get
correct pressure. Make a test for leakage in the
problems that follow.
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TM 5-3805-260-24