Piper COMANCHE PA-24-180 Service Manual page 475

PIPER COMANCHE SERVICE MANUAL
7C-65. Oil Seeen. The uction saeen located in the left side of the engine sump should be cleaned ax each
oil change
remove any accumulation of sludge and to examine for metal firansp or chips. If metal
particles re found in the sceen. the engine should be examined for ternal damage. The sucion screen is
removed from the sump by removing the hex head plug at the lower left side of the sump. Clean and
inspect the screen and gasket and replace the gpker if over compressed or damaged.
7C66. Oil Filter Eement.
a. The oil filter element should be remnved after each fifty hours of engine operation; thi is
accomplished by removing the lockwire from the bolt-head a the end of the filter housing, loosening the
bolt, and removing the filter asembly from the adapter.
b. Before disarding the filter dement, remove the outer perforated paper cover, and using a sharp
knife, cut through the folds of the element at both ends, close to the metal caps. Then, carefully unfold the
pleazed element and examine the materil rapped in the filter for evidence of internal engine damage such
as chips or particles from bearings. In new or newly overhauled engines, some small particles of metallic
shavings might be found; these are generally of no consequence and should not be confusv with particles
produced by nmpacung, abraion or pressure. Evidence of internal engine damage founo n the oil filter
jusifies further examination to determine the cause.
c. After the element has been replaced, tighten the attaching bolt within 15 to 18 foot pounds
torque. Lockwire the bolt through the loops on the side of the housing to the drilled head of the
thermosuac valve. Be sure the lockwre is replaced at both the attaching bolt head and the thermostatc oil
cooler by-pass valve.
7C-67. Turbo Oil Flow Check. (Refer to Figure 7C-17.) Should an indication of low turbo oil pressure or
flow occur, the following system checks may be accomplished.
a. To check oil pressure, use the following procedure:
1. Install a pressure gauge with a range of 0 to 80 ps pressure in the pressure line to the
turbochargers fter the reduction check valve.
2. Start the engine and warm up
in
the usual manner until oil temperature
s
normal.
3. Idle engine at 1000 RPM and observe pressure gauge. It should indicate a minnmum of 15 psi.
Run engine at 2000 RPM the pressure gauge should read minimum of 30 psi and a maximum of 55 psi.
b. To check turbo oil flow, use the following procedure.
1. Ascertain that the engine oil sump is full as indicated on the dipstick.
2. Stur the engine and warm up in the usual manner unnl oil temperature is normal.
3. Stop engine and disconnect oil drain line, of the turbocharger to be checked, it the sump. ig
4. Plug sump connecnon where drain line was disconnected.
5. Install test line, approximately four feet long, on disconnected turbo oil drain line.
6. Set two clean one gallon capacity containers below the engine.
7. Allow the turbo oil drain test line to hang in one container.
8 Start engine and idle at 1000 RPM.
9. When oil flows from the rurbo oil drain line into the container, quickly direct the oil flow into
the empty container and immediately start timing for one minute.
10. When one minute has passed, direct the oil flow into the scavenger container and stop engine.
11. Measure the oil in the test container. it should be a minimum of 0.4 quart.
12. Diconnect test line, remove plug from drain ine tee firting and connect turbo oil dran line to
tee fitting
13 Test oil flow of the other turbocharger unit by using the same procedure.
POWER PLANT
ISSUED: 8/18/72
2 H21