JBM 54347 Manual De Instrucciones página 7

REF.54347
In a cylinder without leakage, the needle will
point to 20% approximately.
Check the remaining cylinders and compare
the percentages of pressure loss.
If the needle shows that there is a leakage, you
should listen in these places:
- Oil dipstick tube
- Radiator filler
- Adjacent cylinder to the cylinder you are
doing the test
- Tail pipe
- Carburetor air inlet
- Fuel injector throttle body
Depending where you hear the air noise you
can determine which is the failure.
Place
Oil dipstick tube
Radiator filler
Adjacent cylinder
to the cylinder you
are making the
test
Tail pipe
Carburetor air
inlet
Fuel injection
throttle body
Helpful suggestions
1. If 100% or excessive leakage shows on gauge
the cylinder may not be at TDC on the com-
pression stroke. Check to ensure that the val-
ves are closed. Always try to position piston at
TDC for uniform results.
2. If rings are broken or cylinder walls are worn
excessive leakage will be shown.
3. It is important that all cylinders have rea-
sonable uniform readings (as in compression
testing). Differences in excess of 15% indicate
excessive leakage.
4. Large engines tend to leak more than small
engines
5. If leak is excessive on a vehicle with low mi-
leage, piston rings may be stuck. Treat engine
with quality tune-up oil for a period of time
and then re-test before disassembling.
Failure
Worn rings.
Worn cylinder wall.
Worn cylinder wall.
Head gasket leakage
Head gasket leakage
Exhaust valve leakage
Inlet valve leakage
Inlet valve leakage
6. The lower the pitch of the air leakage sound,
the greater the leak.
7. To assist with listening use a length of clean
hose, or a mechanic's stethoscope with probe
removed.
8. When making repeat tests on the same
cylinder, variations in the piston position and
engine temperature can cause gauge rea-
dings to differ by up to 10%.
9. If an engine has multiple faults (such as worn
rings and burned valves), the tester may indi-
cate only the OPERATION
MAINTENANCE
Drain the compressor air tank daily.
Clean compressor air inlet filter weekly.
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