Actron KAL2505 User Manual
Professional series, Compression test kit, Instructions for compression test procedure
1. Run the engine for about ten minutes or
until it reaches normal operating
temperature before performing the
compression test.
2. Stop the engine. Disconnect all the
spark plug wires and number them in the
order in which they were removed; this
makes them easy to identify for
reconnection.
3. Loosen all spark plugs about one turn,
but do not remove them. Use an air hose
or stiff brush to remove all the dirt from the
spark plug wells. Remove the spark plugs
and place them on a clean, flat surface in
the order in which they were removed. This
procedure will help to correlate any
compression or cylinder problems with the
condition of the plug from the particular
cylinder involved.
4. Remove the air filter and set the
carburetor throttle plates to the wide open
throttle position using a wooden block,
being careful not to damage the linkage or
carburetor components. See Figure 1.
5. Remove the high tension lead from the
center of the distributor and connect to
ground as shown in Figure 2. To disable
electronic ignition systems, disconnect the
electronic ignition module or remove the
primary battery terminal from the ignition
coil. On GM HEI V-8 and V-6, disconnect
the primary lead from the distributor cap
(Figure 3).
6. Disconnect the hose from the gauge.
Screw the spark plug adapter hose (Item 3,
Figure 6) into a spark plug well. Hand
tighten only DO NOT USE A WRENCH.
See Figure 4.
NOTE: On engines with long reach plugs,
use the long reach adapter (Items 5 and 6,
Fig. 6). Do not use the adapter in short
reach holes it may hit the top of the piston
and damage the engine.
7. Insert the spark plug hose into the
gauge by pulling up on the outer sleeve of
the gauges quick disconnect coupling and
allow it to snap back as the fitting engages
the adapter.
CAUTION!
Failure to return the carburetor
throttle plates to the closed position
before starting the engine can cause
serious engine damage.
8. Crank the engine for at least four
compression strokes or until the pressure
reading stops rising on the gauge.
9. Record the compression reading, then
push the side release valve to relieve the
pressure as shown in Figure 5. Repeat the
test. Record the reading, relieve the pressure,
remove the gauge from the hose, and
remove the hose from the spark plug well.
10.Reconnect the hose to the next spark
plug well to be tested and repeat steps 6
through 10 for the remainder of the
cylinders to be tested.
Test Results
1. On a normal cylinder, the gauge needle
should travel up-scale on each
compression stroke until it reaches a peak
value. All cylinders should indicate a
pressure that is within the vehicle
manufacturers specifications, and the
reading should not vary more than 10%
from cylinder to cylinder.
2. If the needle fails to travel up-scale as
described in Step 1, or if it remains at the
same value for several strokes and then starts
to climb, the cylinder has a sticking valve.
3. If the compression reading is
considerably higher than the vehicle
manufacturers specification, it indicates
carbon build-up in the cylinder.
4. If a reading on two adjacent cylinders is 20
psi (or more) lower than the other cylinders, a
defective head gasket is indicated. Water
(coolant) and oil may be found in the two
cylinders under these conditions.
5. If the readings are low or vary widely
between cylinders, pour a teaspoon of
S.A.E. grade 30 oil into each cylinder and
retest. If the readings increase considerably,
the fault may be due to poorly seated or
worn piston rings. If the readings remain
about the same, the valves and/or
associated components are the likely cause.
6. Clean, regap, and reinstall the spark
plugs in the same order in which they were
removed, or install new spark plugs.
Reconnect all spark plug wires in the proper
order. Remove the wooden block from the
carburetor throttle plates and make certain
they return to closed throttle position.
Reconnect the ignition system wiring, which
was disconnected in Step 5, TEST
PROCEDURE.
Compression Test Kit
Instructions for Compression Test Procedure
Key Part Number Description
1
0031-0255
Compression Gauge
2
0180-0772
Quick Disconnect Coupling
and Valve Assembly
3
0032-0112
14MM (Std) Spark Plug Hose
Assembly
4
0032-0113
18MM (Std) Spark Plug Hose
Assembly
5
0180-0895
14MM Long Reach Adapter
6
0180-0896
18MM Long Reach Adapter
7
0180-0894
12MM Adapter
8
0180-0893
10MM Adapter
9
*
Air valve (High Pressure)
10 *
O-Ring 14MM
11 *
O-Ring 18MM
12 *
O-Ring 10MM
13 *
O-Ring 12MM
14 0001-002-1644Instruction Label (not shown)
15 0400-1346
Carry Case (not shown)
includes item 14
16 *1000-2045
Repair Kit: includes five Air
Valves item 9, eight O-Rings
(two each) items 10, 11, 12, 13
Air Valve Tool (not shown)
0001-002-1644
Professional Series
Figure 6
Compression Gauge
Repair Parts
0
0
30
60
90
120
150
210
180
240
270
300
2
4
6
8 10 12
14
16
18
20
kPa x 100
Compression
Tester
0
0
30
60
90
120
150
210
180
240
270
300
2
4
6
8 10 12
14
16
18
20
kPa x 100
Compression
Tester
0
0
30
60
90
120
150
210
180
240
270
300
2
4
6
8
10 12
14
16
18
20
kPa x 1
00
Compression
Tester
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All rights reserved.