Differential Pressure Tester; Static Seal Check - Continental Motors TSIO-520-BE Maintenance And Operator's Manual

CAUTION . .. Care must be exercised in opening the cylinder pressure valve, since sufficient air pressure
will be built up in the cylinder to cause it to rotate the crankshaft if the piston is not at TDC.
It
is
recommended that someone hold the propeller during check to prevent possible rotation.
5. Open the cylinder pressure valve completely. Check the regulator pressure gage and adjust, if necessary
to 80 p.s.i.
6.
Observe the pressure indicatior on the cylinder pressure gage. The difference between this pressure
shown by the regulator pressure gage is the amount of leakage through the cylinder. If the cylinder pressure
gage reading is higher than the previously determined master orifice calibrated pressure reading, proceed
to the next cylinder leak check. If the cylinder gage reading is lower, proceed with the following.
REGULATOR
PRESSURE
GUAGE
'
COMPRESSED '-
AIR SOURCE
f
;;;.~:
~
' : t' " ""'
(HANO TIGHT)
REGULATOR
PRESSURE
GUAGE
COMPRESSED
AIR SOURCE
FIGURE 9-3. DIFFERENTIAL PRESSURE TESTER
Static Seal Check (See Figure 9-5)
CY UNDER
ADAPTER
7. The source of air leakage should first be checked for the static seal. Positive identification of static seal
leakage is possible by listening for air flow sound at the exhaust or induction system cylinder port. When
checking the cylinder head to barrel leakage, use a soapy solution between the fins and watch for bubbles.
use a soapy solution also around both spark plugs seals for leakage. NO LEAKAGE IS ALLOWED IN STATIC
SEALS.
8. If leakage is occurring in the intake or exhaust valve areas, in may be possible to correct a low reading
by staking the valves. This is accomplished by placing a fiber drift on the rocker arm directly over the valve
stem and tapping the drift several times with a hammer to dislodge any foreign material that may be between
the valve face and seat.
CAUTION ... When correcting
a
low reading in this manner, rotate the propeller so the piston will not be
at TDC. This is necessary to prevent he valve from striking the top of the piston in some engines. Rotate the
propeller again before rechecking leakage to reset the valves in the normal manner.
NOTE ... When the rocker cover is removed, inspect valve spririgs, valve retainers and valve stem for wear.
This may have contributed to the valve leakage.
9-9