Eastern Technology's Differential Cylinder Pressure Testers quickly locate worn and cracked rings, defective intake and exhaust valves, scored and cracked
cylinders, leaky head gaskets, and worn and stripped spark plug bushings; virtually every potential cause of pressure loss.
Pictured is Eastern's Model E2M Tester, for cylinders of less than a 5.00 inch bore* with a .040 inch diameter orifice, that eliminates all guess-work by
enabling you to determine the exact location and cause of your engine's efficiency loss. This tester is recommended by TCM Service Bulletin SB03-3.
For Cylinders with a 5.00 inch bore and over order our Model E2M-1000 with a .060 inch diameter orifice.
*(Per F.A.A. Ac 43.13-iB Chapter 8, 8-14) This product is protected under patent claims issued and/or pending. Warning: This device is for use with aircraft by qualified A.P. Technicians only. All aircraft tests
should be performed by two technicians. Air pressure can cause the propeller to rotate suddenly
and without warning. It is not possible for one individual to safely perform these tests on aircraft.
Setup
If you are testing a certified aircraft engine, perform Master Orifice Test. See Master Orifice manufacturer’sdocumentation for procedure.
Run engine until it reaches normal operating temperature.
Remove the most accessible spark plug from each cylinder.
Set the Master Orifice Valve to the Off position; handle vertical and pointing down.
After making sure the Slow Fill Valve is Off, connect an air source to the tester, via the male
quick connect fitting. Air source must be at least 90 PSI.
Pull Pressure Regulator knob to unlock, and adjust so the left hand gauge reads 80 PSI.
Operation
Hand tighten Test Adapter, with O Ring and hose, into cylinder under test.
Place a thumb over the end of the hose fitting and rotate the prop until the piston’s compression
blows thumb off hose end. This will place the female quick connect fitting.
Connect the hose from the cylinder under test to the tester via the female quick connect fitting.
Slowly open the Slow Fill Valve approximately 1/8 Turn (3 or 4 tick marks), until moderate
resistance is felt at the prop. Carefully rotate the prop back and forth through TDC until a positive
detent is felt, and the air pressure holds the prop at Top Dead Center.
Warning: Cylinder pressure will slowly rise to 80 PSI, and prop may rotate. Exercise caution.
Open the Slow Fill Valve completely; handle horizontal, parallel to the Pressurize Label.
If necessary, readjust the regulator to 80 PSI at the left hand gauge.
Read the relative pressure in the cylinder under test, at the right hand gauge.
To Test Another Cylinder
Set the Slow Fill Valve to the Off position, and allow the cylinder pressure to bleed off. The
right hand gauge will slowly return to zero. There is no need to turn down the regulator pressure.
When the right hand gauge reads to zero, with the Slow Fill Valve still closed, remove the test
hose from the female quick connector.
Remove the Test Adapter from the cylinder just tested, and hand tighten it into the next cylinder.
Repeat the OPERATION procedure, listed above.
IMPORTANT
Ambient barometric pressure can significantly alter differential pressure readings. Good practice
indicates that a Master Orifice Test be run every day, and preferably prior to every engine test.
Always run a Master Orifice Test if an engine shows marginal readings, if noticeable weather
changes occur, or if ground level altimeter settings change. Refer to the instructions and
specifications provided with your Master Orifice, for proper procedure.
All cylinders will exhibit a certain amount of leakage due to standard engine clearance and normal
wear; no cylinder is expected to maintain a perfect 80 PSI. It is important that all cylinders show
relatively consistent readings. Good judgement should be used as to the allowable tolerance
between cylinders. Always consult the manufacturers’ engine specifications.
Tips
By listening for escaping air at key engine locations, you can generally determine the source of
low pressure readings:
Air Escaping from Carburetor Intake: Indicates Leaking Intake Valve
Air Escaping from Exhaust System: Indicates Leaking Exhaust Valve
Air Escaping from Crankcase Breather: Indicates Defective Rings
Air Escaping from Radiator: Indicates Defective Head Gasket or Cracked Head/Block
Master Orifice Test
This test is run with no connections to the female quick connector.
Set the Master Orifice Valve to the Off position; handle horizontal and directly over the Off Label.
Set the Slow Fill Valve (next to the Pressure Regulator) to the Off position; handle vertical and
pointing down.
After making sure the Slow Fill Valve is Off, connect an air source to the tester, via the male
quick connect fitting. Air source must be at least 90 PSI.
Adjust Pressure Regulator so left hand gauge reads 80 PSI.
Set the Master Orifice Valve to the Test position; handle vertical and pointing down.
Open the Slow Fill Valve completely; handle horizontal and over the Pressurize Label.
If necessary, readjust the regulator to 80 PSI at the left hand gauge.
Read the relative pressure at the right hand gauge. Eastern Technology Corporation agrees to repair or replace any of its products (parts and labor) if there is a defect in materials or workmanship within one year of the date of purchase. Eastern
Technology Corporation limits its obligation to repair or replacement, the choice of which is at its sole discretion. This warranty does not apply to equipment that has been damaged by accident, negligence, or misuse, or altered or modified in any way. |
