Panasonic U-16GE3E5 Use and care manual

Gas Heat Pump
Air Conditioner
Applicable Models
2WAY MULTI/W MULTI
U-16GE3E5
U-20GE3E5
U-25GE3E5
U-30GE3E5
3WAY MULTI
U-16GF3E5
U-20GF3E5
U-25GF3E5
Reference No. GMP-1703-01A
Main Parts Replacement
March 2017
Order No. SBPAC1612011CE

Table of Contents
Basic Operation
1. Safety Precautions................................................................................................ 1
2. Preparation for work ............................................................................................. 2
3. Basic Operations for Periodic Inspection Work................................................. 3
4. Basic Operation for Shutoff Valves of W MULTI................................................. 5
5. Basic Operation for Shutoff Valves of 3WAY MULTI .......................................... 6
Table.1 Built-in Engines for GHP Models ( is built-in engine)
Engine
GHP model K25 engine
2WAY MULTI/
W MULTI
U-16GE3E5
U-20GE3E5
U-25GE3E5
U-30GE3E5
3WAY MULTI
U-16GF3E5
U-20GF3E5
U-25GF3E5
Engine Cylinder Head Inspection and Replacement Procedure
1. Required parts and tools used ............................................................................ 7
2. Preparation for work ............................................................................................. 7
3. Coolant discharge ................................................................................................. 7
4. Disconnect all lead wires...................................................................................... 8
5. Disconnect all hoses............................................................................................. 9
6. Remove exhaust gas heat exchanger ................................................................11
7. Remove intake manifold and exhaust manifold ................................................12
8. Remove rocker cover ...........................................................................................12
9. Remove ignition coils ..........................................................................................12
10. Remove ignition coil bracket...............................................................................13
11. Remove spark plugs ............................................................................................13
12. Remove cylinder head assembly........................................................................14
13. Strip and clean gasket (Figure18) .......................................................................15
14. Attach cylinder head ............................................................................................16
15. Valve clearance adjustment procedure..............................................................17
16. Install the rocker cover (Figure 26).....................................................................18
17. Spark plug installation (Figure 27) .....................................................................18
18. Install ignition coil bracket ..................................................................................19
19. Install ignition coils..............................................................................................19
20. Install intake manifold and exhaust manifold....................................................19
21. Install exhaust gas heat exchanger................................................................... 20
22. Reconnect all hoses.............................................................................................21
23. Connect all lead wires..........................................................................................21
24. Install other parts .................................................................................................21
25. Preparation for operation ................................................................................... 22
26. Coolant Replenishment ...................................................................................... 22
27. Final check........................................................................................................... 22

Starter Replacement Procedure
1. Required parts and tools used .......................................................................... 23
2. Preparation for work ........................................................................................... 23
3. Remove starter .................................................................................................... 23
4. Install starter........................................................................................................ 23
5. Preparation for operation ................................................................................... 23
6. Final check........................................................................................................... 23
Ignition Electrical Parts Inspection and Maintenance
1. Required parts and tools used .......................................................................... 24
2. Preparation for work ........................................................................................... 24
3. Ignition coils (with built-in power transistors) ................................................. 24
4. Crank angle sensor (Figure 2)............................................................................ 24
5. Cam angle sensor ............................................................................................... 25
6. Spark plugs.......................................................................................................... 25
7. Preparation for operation ................................................................................... 26
8. Final check........................................................................................................... 26
Ignition Timing Check and Adjustment
1. Preparation for work ........................................................................................... 27
2. Distributor mode setting .................................................................................... 27
3. Start test operation and set engine rotational speed ...................................... 28
4. Ignition timing check .......................................................................................... 29
5. Correction for distorted amount........................................................................ 30
6. Cancel settings.................................................................................................... 33
7. Stop test run ........................................................................................................ 34
8. Final check........................................................................................................... 34
Front Oil Seal Replacement Procedure
1. Required parts and tools used .......................................................................... 35
2. Preparation for work ........................................................................................... 35
3. Remove compressor drive belt.......................................................................... 35
4. Remove the crank pulley .................................................................................... 35
5. Remove front cover oil seal (Figure 2)............................................................... 35
6. Install the front cover oil seal (Figure 3)............................................................ 36
7. Install the crank pulley........................................................................................ 36
8. Install the compressor drive belt....................................................................... 36
9. Preparation for operation ................................................................................... 36
10. Final check............................................................................................................37
Rear Oil Seal Replacement Procedure
1. Required parts and tools used .......................................................................... 38
2. Preparation for work ........................................................................................... 38
3. Removetheywheel........................................................................................... 38
4. Remove the oil seal............................................................................................. 38
5. Oil seal installation.............................................................................................. 39
6. Preparation for operation ................................................................................... 39
7. Final check........................................................................................................... 39

Fuel Gas Piping Replacement Procedure
1. Required parts and tools used .......................................................................... 40
2. Preparation for work ........................................................................................... 40
3. Removal................................................................................................................ 40
4. Remove the pipe bracket.................................................................................... 40
5. Install the pipe bracket ....................................................................................... 40
6. Installation ............................................................................................................41
7. Preparation for operation ....................................................................................41
8. Final check............................................................................................................41
Coolant Three-way Valve and Hot Water Three-way Valve Replacement
Procedure
1. Required parts and tools used .......................................................................... 42
2. Preparation for work ........................................................................................... 42
3. Prepare to remove the three-way valve............................................................. 42
4. Remove the three-way valve (Figure 1) ............................................................. 42
5. Install the three-way valve.................................................................................. 42
6. Preparation for operation ................................................................................... 42
7. Coolant Replenishment ...................................................................................... 42
8. Final check........................................................................................................... 43
Expansion Valve, Liquid Valve, Bypass Valve and Waste Heat Recovery
Valve Replacement Procedure
1. Required parts and tools used .......................................................................... 44
2.
Prepare to remove the expansion valve, liquid valve, bypass valve and waste
heat recovery valve..................................................................................................44
3. Preparation for work ........................................................................................... 44
4.
Prepare to remove the expansion valve, liquid valve, bypass valve. and waste
heat recovery valve. ..................................................................................................45
5. Install the expansion valve, liquid valve, bypass valve and waste heat
recovery valve. .................................................................................................... 46
6. Preparation for operation ................................................................................... 46
7. Final check............................................................................................................47
Pressure Sensor Replacement Procedure
1. Required parts and tools used .......................................................................... 48
2. Remove pressure sensor.................................................................................... 48
3. Install pressure sensor ....................................................................................... 49
4. Preparation for operation ................................................................................... 52
5. Final check........................................................................................................... 52
Coolant Pump Replacement Procedure
1. Required parts and tools used .......................................................................... 53
2. Preparation for work ........................................................................................... 53
3. Prepare to remove the coolant pump................................................................ 53
4. Remove the coolant pump ................................................................................. 53
5. Coolant pump installation .................................................................................. 54
6. Preparation for operation ................................................................................... 54
7. Fill up with coolant.............................................................................................. 54
8. Final check........................................................................................................... 54

Coolant Check, Replenishment, and Replacement Procedure
1. Required parts and tools used .......................................................................... 55
2. Preparation for work ........................................................................................... 55
3. Check and replenish coolant ............................................................................. 55
4. Coolant replacement........................................................................................... 56
5. Coolant pump operation and stopping procedures......................................... 60
Compressor Replacement Procedure
1. Required parts and tools used .......................................................................... 62
2. Prepare to remove the compressors................................................................. 62
3. Preparation for work ........................................................................................... 62
4. Remove the compressor .................................................................................... 62
5. Install the compressor........................................................................................ 65
6. Preparation for operation ................................................................................... 67
7. Final check........................................................................................................... 67
Fan Motor Replacement Procedure
1. Required parts and tools used .......................................................................... 68
2. Preparation for work ........................................................................................... 68
3. Remove the fan motor ........................................................................................ 68
4. Install the fan motor ............................................................................................ 69
5. Preparation for operation ....................................................................................70
6. Final check............................................................................................................70
Pump Down Procedure (Common to Cooling and Heating)
1. Select the pump-down mode. .............................................................................71
2. Stop operation for all indoor units .....................................................................71
3. Remove refrigerant shutoff valve cap ................................................................71
4. Attach the gauge manifold ..................................................................................71
5. Operating the refrigerant shutoff valve (* 3WAY MULTI only) ..........................73
6. Start the test run: Carry out a test run on the outdoor unit.............................74
7. Conguretheforcedclosesettingofthebypassvalve. ..................................75
8. Set engine rotational speed ................................................................................76
9. Fully shut off the refrigerant liquid shutoff valve............................................. 77
10. Fully open the refrigerant gas shutoff valve..................................................... 77
11. Disconnect the gauge manifold......................................................................... 77
12. Stop outdoor unit .................................................................................................78
13. Cancel setting.......................................................................................................78
14. Turn off fuel supply *Carry out this if necessary. .............................................78
Mixer Cleaning Procedure
1. Required parts and tools used .......................................................................... 79
2. Preparation for work ........................................................................................... 79
3. Mixer cleaning procedure................................................................................... 79
4. Preparation for operation ................................................................................... 79
5. Final check........................................................................................................... 79
Reference Document
Refrigerant, Coolant, Fuel, Air Supply and Exhaust, and Engine Oil Filling
System.................................................................................................................. 80
Bolt Tightening Torque Table ..................................................................................... 85

1
Basic Operation
1. Safety Precautions
(1) W MULTI
Safety Precautions
Stopping only the indoor unit is extremely dangerous because the engine may suddenly start if the customer
operates the remote controller on the indoor unit side. Before carrying out work on the inside of the outdoor unit,
perform the STOP operation for the outdoor unit, check the “  ” indication, and then make sure
you turn off the power supply circuit breaker of the outdoor unit. Furthermore, before carrying out the backup
operation, close the closing valves of all outdoor units for which the stop operation has been performed.
(2) Models other than W MULTI
Safety Precautions
Stopping only the indoor unit is extremely dangerous because the engine may suddenly start if the customer
operates the remote controller on the indoor unit side. Before carrying out work on the inside of the outdoor
unit, make sure you turn off the power supply circuit breaker of the outdoor unit.(However, if a system controller
or other centralized control device is being used, an abnormal communications error may be generated.)
Alternatively, perform the STOP operation for the outdoor unit.
Basic Operation

2
Basic Operation
2. Preparation for work
(1) Turn off remote controls for all indoor units.
(2) Stop outdoor unit
W MULTI
 Move the STOP SW (SW001) shown in gure 1 from “NORM” to “STOP”. The 7 segment LEDs in gure 2
will display “  ”.
 Check that the engine is stopped.
 Close the three shutoff valves for the refrigerant gas pipe, refrigerant liquid pipe, and balance pipe.
 The all stop operation will begin.Note: Even if the all stop operation is performed for one unit, an indoor unit
can be operated by the backup operation. When the STOP operation is performed for all outdoor units, an
outdoor unit cannot be started even with a command of the indoor unit.
 After 3 minutes has elapsed since the display of the “  ” indication in the seven-segment
LED display of Figure 2, the “  ” indication in the seven-segment LED display of Figure 3 is
displayed.
 Turn off the power supply circuit breaker for the outdoor unit.
Models other than W MULTI
 Turn off the power supply circuit breaker for the outdoor unit.
 Alternatively set the STOP-SW (SW001) in Figure 1 from the NORM side to the STOP side.The seven-
segment LED display of Figure 2 displays the “  ” indication.
 The all stop operation will begin.
(3) Turn off the fuel system.
Close the main gas valve, cutting off the fuel supply.
Figure.1 Figure.2
Figure.3

3
Basic Operation
3. Basic Operations for Periodic Inspection Work
All work other than when the STOP (all stop) switch (SW001) is set to STOP and the VG (fuel solenoid valve forced
off switch) switch (SW002) is set to OFF should be performed with the HOME (SW004), SET (SW007), UP (SW005),
and DOWN (SW006) keys.
It is extremely dangerous if the customer performs an operation that runs the engine during a maintenance inspection
or when not expected. Make sure you stop operation during work in the way described below.
* Pressing the HOME (SW004) key for 1 second or more forcefully returns the state to the initial state. The
value of a partially set item will be discarded, and the item number will return to “  .”
* If there is no operation for 10 minutes when other than the “  ” item number is displayed, the value of
a partially set item will be discarded, and the item number will return to “  .”
(1) Backup operation during maintenance work (for W MULTI)
● What is backup operation?
In the GHP W MULTI series, multiple outdoor units are connected to the same refrigerant tube. Therefore,
even during maintenance work of an outdoor unit, the other outdoor unit not required in maintenance work can
be used to keep the indoor operating conditions. This is called a backup operation.
● Backup operation procedure
To perform backup operation, the outdoor unit for maintenance work (hereafter referred to as “target outdoor
unit”) must be cut off from the system using the following procedure. Review content of the maintenance work
and then select the most suitable method.Also, after the maintenance work is nished, always refer to [System
recovery procedure] and then return the system to its normal state.
[Backup operation procedure]
To turn off power of target outdoor unit and then perform maintenance work (basic operation during
inspection of outdoor unit)
<<Important>>
This is the basic operation performed during inspection work. If this operation is not performed and the
power of the outdoor unit is turned off, this will cause system fault and prevent backup operation to be
carried out, and serious malfunction will occur. If this happens, see [System recovery procedure] to recover
the system, and then once again use the following procedure to perform setup. Automatic backup operation
will kick in.
<<Step 1>>
On the outdoor main board of the target outdoor unit,
set the STOP switch (SW001) to “STOP”. *1
<<Step 2>>
(After conrming that the engine of the tar get outdoor
unit is stopped) close the valves of refrigerant gas tube,
refrigerant gas liquid tube, and balance tube.
<<Step 3>>
On the outdoor main board of the target outdoor unit,
set the STOP switch (SW001) to “STOP”. Wait for
three minutes or more and then turn off the circuit
breaker of the target outdoor unit. *2
Start maintenance work.

4
Basic Operation
*1) Sometimes all outdoor units may stop. If there is operation input, outdoor units other than the target one will
start operation again after approximately ve minutes. (For details on the settings, see the next item.)
*2) Always carry out the following three tasks.
 Check to make sure <<Step 2>> is nished. If the shutoff valve is opened, refrigerant will ow from the
other outdoor unit to the target outdoor unit, causing serious malfunction.
 After three minutes has elapsed from completion of <<Step 1>>, check to make sure the outdoor main
board displays “  ” and then perform this operation. If you turn off the power immediately
after performing “STOP” setting, the entire system will stop. (Backup operation cannot be performed.) If
this happens, see [System recovery procedure], recover the system, and then start over again starting from
<<Step 1>>.
 There will not be any problem whether the circuit breaker of the outdoor unit in <<Step 3>> is ON or OFF.
Select one of them according to the work required.
[Work example] Perform maintenance on W MULTI outdoor unit 2 in refrigerant system 1.
Refrigerant System 1
Refrigerant tubing (main tubing)
Refrigerant tubing(Outdoor
branch tubing)
W MULTI
outdoor unit
1
Indoor/outdoor control wiring
<<Step 1>>
<<Step 2>>
<<Step 3>>
W MULTI
outdoor unit
2
a) For the W MULTI outdoor unit 2 indicated in the left diagram,
perform <<Step 1>> to <<Step 3>> in [Backup operation
procedure] in that order. Then, perform maintenance work on W
MULTI outdoor unit 2.
b) When <<Step 3>> is nished, W MULTI outdoor unit 1 is reset. (It’ll
stop even if it is operating.)
c) After approximately ve minutes, if there is operation input (indoor
remote controller is “Run” or test run setting on outdoor main
board), W Multi outdoor unit 1 starts up. (Backup operation starts.)
d) If test run is set from outdoor main board, W MULTI outdoor unit
1 continues to run. However, if normal operation is started by the
indoor remote controller, depending on the load, all outdoor units
may stop due to thermostat off.
[System recovery procedure]
If backup operation has been performed, by all means check the following items after the maintenance work,
and then perform settings again to return the system to its normal state.
 Check to make sure all shutoff valves of refrigerant gas tube, refrigerant liquid tube, and balance tube of the
outdoor unit are opened.
 Check to make sure the STOP switch (SW001) on the outdoor main board is set to “NORM”.
 If the power of the outdoor unit has been turned off, turn on the circuit breaker.
 If “Test run” (No.4 Test- Cool/Heat) is set, cancel it.
* When adjusting to No.4 Test-Cool or Heat, if TEST/WARNING LED (LED052) lights, this means “Test
run” is being set. In this state, press the SET (SW007) key for one second or more. The setting will be
canceled (TEST/ WARNING LED (LED052) goes off.)

5
Basic Operation
4. Basic Operation for Shutoff Valves of W MULTI
(1) Opening and closing of shutoff valves
Ball valves are used for the shutoff valves on the outdoor unit, so they can be opened and closed by rotating the
tab 90 degrees.
● Remove the cap with a monkey wrench.
● Gently and steadily turn the tab to the left (counterclockwise) by 90 degrees. (Same for the refrigerant gas tube,
refrigerant liquid tube)
The valve is fully open when the tab has been rotated 90 degrees (when it contacts the stopper). Do not try to
rotate it any further.
* The valve is fully closed when the slit of the tab is at right angles to the pipe, and fully open when the slit
of the tab is parallel to the tube.
Fully closed
Refrigerant
gas tube
Refrigerant
liquid tube
Refrigerant
gas tube
Refrigerant
liquid tube
Fully opened
Note 1): If the unit is operated while the closing valves are still closed, the discharge pressure of the refrigerant
will rise to an abnormal level, and the compressor, the four-way valves, and other parts will be damaged.
Note 2): Be sure to close the valves when performing the forced backup operation. If another unit is operated,
refrigerant will enter into and collect in the stopped outdoor unit.

6
Basic Operation
5. Basic Operation for Shutoff Valves of 3WAY MULTI
(1) Opening and closing of shutoff valves
Ball valves are used for the shutoff valves on the outdoor unit, so they can be opened and closed by rotating the
tab 90 degrees.
● Remove the cap with a monkey wrench.
● Gently and steadily turn the tab to the left (counterclockwise) by 90 degrees. (Same for the refrigerant suction
tube, refrigerant discharge tube, and refrigerant liquid tube)
The valve is fully open when the tab has been rotated 90 degrees (when it contacts the stopper). Do not try to
rotate it any further.
* The valve is fully closed when the slit of the tab is at right angles to the pipe, and fully open when the slit
of the tab is parallel to the pipe.
Fully closed Fully opened
Refrigerant
suction tube
Refrigerant
Liquid tube
Refrigerant
discharge
tube
Refrigerant
suction tube
Refrigerant
discharge
tube
Refrigerant
Liquid tube
Note 1): If the unit is operated while the closing valves are still closed, the discharge pressure of the refrigerant
will rise to an abnormal level, and the compressor and other parts will be damaged.

7
Engine Cylinder Head Inspection and Replacement Procedure
1. Required parts and tools used
Part names and tools used Remarks
Sparkplug wrench Width across at: 16 mm
Valve spring replacer Special tool
Gasket stripper spray As needed
Scraper 1
Rubber stopper
Sponge As needed
Thickness gauge 1
Straight edge 1
Binding band (clamper) As needed
Timing light 1 set
Cylinder head bonding and gasket kit 623-333-1942
Cylinder bolt set (10 bolts) 623-332-7549
Torque wrench 7.6N·m 25.0N·m 38.2N·m
15.7N·m 29.4N·m 45.6N·m
23.6N·m 34.4N·m 48.2N·m
Engine oil Small amount of Panasonic genuine AP. GHP D -125
Small amount of Panasonic genuine GHP Oil 10TH
Small amount of Panasonic genuine GHP Oil
10W30C2
Socket wrench set 1 set
Extension bar Approx. 75, 150 mm long
Stem seal insertion tool 1 set
General tools 1 set
2. Preparation for work
(1) If coolant temperature is high, lower it.
See “Coolant Check, Replenishment, and Replacement Procedure” in this manual for coolant pump operation
and stopping procedures.
(2) See “1. Safety Precautions” and “2. Preparation for work” of “Basic Operation” in this manual.
3. Coolant discharge
For details about the coolant discharge procedure, see “Coolant Check, Replenishment, and Replacement
Procedure.”
Engine Cylinder Head Inspection and Replacement Procedure

8
Engine Cylinder Head Inspection and Replacement Procedure
4. Disconnect all lead wires
(1) Remove the ignition coil connectors (gray, 3P, 4
locations). (Figure 1)
(2) Remove the coolant temperature sensor connector
(green, 2P). (Figure 2)
(3) Remove the stepping motor connector (white, 6P)
and the fuel adjustment valve connector (red, 6P)
(4) Move the lead wires to the right, so that they do not interfere with subsequent work.
Figure.1
Ignition coil connectors
Figure.2
Coolant temperature
sensor connector
Figure.3
Fuel gas adjustment valve Stepping motor

9
Engine Cylinder Head Inspection and Replacement Procedure
5. Disconnect all hoses
Important
When each coolant hose is removed, be sure to use a plastic bag to catch the liquid remaining in the hose, keeping it
from splashing in the surrounding area.
(1) Coolant hose (engine outlet side) (Figure 4)
(2) Equalizer hose (Figure 4)
(3) Blow-by hose (Figure 4)
(4) Coolant hose (from coolant pump to exhaust gas
heat exchanger) (Figure 5)
(5) Coolant hose (from exhaust gas heat exchanger to
engine) (Figure 5)
(6) Exhaust hose (from exhaust gas heat exchanger to
mufer) (Figure 5)
(7) Coolant hose (engine inlet side) (Figure 6)
Figure.4
Blow-by hose
Equalizer hose
Coolant hose
(Engine outlet)
Figure.5
Figure.6
Coolant hose (engine inlet side)
Coolant hose (from exhaust gas heat
exchanger to engine)
Exhaust hose (from exhaust gas
heat exchanger to muffler)
Coolant hose (from coolant pump
to exhaust gas heat exchanger)

10
Engine Cylinder Head Inspection and Replacement Procedure
(8) Fuel gas hose (Figure 7)
Hose Clamp (width across at) 7 [mm]
(9) Intake hose (mixer side) (Figure 7)
Hose Clamp (width across at) 7 [mm]
(10) Intake hose (air cleaner side) (Figure 8)
Hose Clamp (width across at) 7 [mm]
Figure.7
Fuel gas hose
Air intake hose
Intake hose (air cleaner side)
Figure.8

11
Engine Cylinder Head Inspection and Replacement Procedure
6. Remove exhaust gas heat exchanger
(1) Remove the 4 nuts indicated by arrows in Figure 9-1 and 9-2.
Nut (width across at) 17 [mm]
Figure.9-1 (45.0, 56.0, 71.0 kW Type)
Nuts
Nuts
Figure.9-2 (85.0 kW Type)
(2) Remove the 6 nuts, bolts and hexagon socket head bolts indicated by arrows in Figure 10-1 and 10-2, and
remove the exhaust gas heat exchanger.
Bolt (width across at) 17 [mm]
Nut (width across at) 12 [mm]
Figure.10-1 (45.0, 56.0, 71.0 kW Type
(except 3WAY 71.0 kW Type))
Nuts Bolts Hexagon socket head bolt
Figure.10-2 (85.0 kW Type,
3WAY 71.0 kW Type)
Bolts

12
Engine Cylinder Head Inspection and Replacement Procedure
7. Remove intake manifold and exhaust manifold
Remove 10 bolts and nuts indicated by arrows in Figure 11,
and remove with mixer and stepping motor still attached to
intake manifold.
Bolt/nut (width across at) 14 [mm]
● After removing the intake manifold, remove the exhaust
manifold.
8. Remove rocker cover
Remove the cap nuts at the 2 locations indicated by arrows
in Figure 12, remove rocker cover.
Nut (width across at) 22 [mm]
Caution
Do not lose the seal washer under the cap nut.
9. Remove ignition coils
Remove the bolts securing the ignition coils, and remove
the ignition coils. (indicated by arrows in Figure 13)
Bolt (width across at) 10 [mm]
Caution
Handle the ignition coils carefully. Keep them free from
shock.
Figure.11
Nuts (no flange)
Bolts (2)
Flanged nuts
Figure.12
Cap nut
Seal washer
Cap nuts
Figure.13
Ignition coils
Ignition coil retaining bolts (4)

13
Engine Cylinder Head Inspection and Replacement Procedure
10. Remove ignition coil bracket
(1) Remove 2 securing bolts indicated by Figure 14,
remove ignition coil bracket.
Bolt securing the bracket
(width across at) 12 [mm]
11. Remove spark plugs
Using a spark plug wrench, remove all 4 sparkplugs. (Figure
15)
Figure.14
Bolts securing the bracket Ignition coil bracket
Figure.15

14
Engine Cylinder Head Inspection and Replacement Procedure
12. Remove cylinder head assembly
● Take out push rods.
Take out and lay out the push rods and each associated
part separately for the cylinders and the intake and
exhaust.
Adjustment nut (width across at) 14 [mm]
Valve rocker shaft bolt (width
across at) 12 [mm]
● When taking out the valve rocker shaft, if you slightly
compress the coil springs and tie the rocker arms with
wire as shown in Figure 16 before loosening the bolts,
reassembly will become easier.
● Remove the cylinder head bolts.
● Remove the cylinder head gasket.
Caution
To prevent distortion of the cylinder head when loosening
the cylinder head bolts, loosen them gradually in the order
shown in Figure 17.
Bolt (width across at) 14 [mm]
Figure.16
Valve rocker bolt
Screw
Adjustment nut
Compress and tie the rocker
arm coil springs with wire. Use
wire 0.5 - 0.8 mm in diameter
Coil spring
Rocker arm
Push rod
Valve rocker
shaft
Figure.17

15
Engine Cylinder Head Inspection and Replacement Procedure
13. Strip and clean gasket (Figure18)
(1) Prevent entry of foreign matter by using rubber
stoppers or sponges to close off attachment holes,
and also coolant and oil circulation holes on top of
the cylinder block.
(2) Using a scraper, strip any gasket material adhering
to the upper surface of the cylinder block and any
carbon from the piston head area.
(3) Just as for the cylinder block, prevent entry of
foreign matter by using rubber stoppers or sponges
to close off circulation holes in the cylinder head.
(4) Strip gasket material adhering to the cylinder head,
and remove carbon and sludge adhering inside
circulation channels.
(5) Clean each circulation hole in the cylinder head by blowing with compressed air.
(6) Strip gasket material from and clean both the attachment areas for the intake manifold, exhaust
manifold, and the exhaust gas heat exchanger using the same procedure as described for the cylinder
head above.
Caution 1
Make absolutely sure no foreign matter falls into any circulation hole in the cylinder block.
Doing so will cause malfunctions during operation.
Caution 1
Make absolutely sure not to damage the cylinder block surface or the gasket surface on the cylinder head. Damage
will cause malfunctions during operation.
Important
To make gasket stripping easier, apply a solvent like Nihon Kohzai NX66 Gasket stripper spray, and let it soak for
several minutes.
Figure.18