Disassembly Of 4-Valve Cylinder Head - Yanmar 3TNV82A Service Manual

4-Valve Cylinder Head
1 – Crankcase Breather Cover
2 – Diaphragm Spring
3 – Diaphragm Cup
4 – Crankcase Breather Diaphragm
5 – Oil Fill Cap
6 – Valve Cover Nut
7 – Valve Cover Nut O-Ring
8 – Valve Cover Gasket
9 – Support Bolt
10 – Rocker Arm Shaft Support
11 – Wave Washer
12 – Fuel Injector Retainer Bolt
13 – Valve Adjusting Screw (Primary)
14 – Valve Adjusting Screw Lock Nut (Primary)
15 – Rocker Arm Shaft Aligning Stud
16 – Fuel Injector Retainer
17 – Valve Stem Seal
18 – Valve Guide
19 – Cylinder Head
20 – Intake Valve
21 – Exhaust Valve
22 – Cylinder Head Gasket
23 – Fuel Injector Nozzle Protector
24 – Fuel Injector Nozzle Seat
25 – Valve Spring
26 – Valve Bridge Guide
27 – Spring Retainer
28 – Valve Keepers
29 – Valve Bridge
30 – Valve Bridge Seat
31 – Valve Adjusting Screw Lock Nut
(Secondary)
32 – Valve Adjusting Screw (Secondary)
33 – Push Rod
34 – Rocker Arm Shaft
35 – Crankcase Breather Components
36 – Valve Cover
Disassembly of 4-Valve Cylinder
Head
Prepare a clean, flat working surface on a
workbench large enough to accommodate the
cylinder head assembly. Discard all gaskets,
O-rings and seals. Use new gaskets, O-rings and
seals on reassembly of the cylinder head.
1. Drain the coolant from the engine into a suitable
container. See Drain, Flush and Refill Cooling
System With New Coolant on page 5-35.
TNV DI Service Manual
CAUTION
Identify all parts and their location using
an appropriate method. It is important
that all parts are returned to the same
position during the reassembly process.
2. Remove the high pressure fuel injection lines
(Figure 6-37, (1)). See Removal of Fuel
Injectors on page 7-31.
(1)
(3)
Figure 6-37
CAUTION
Remove or install the high-pressure fuel
injection lines as an assembly whenever
possible. Disassembling the
high-pressure fuel injection lines from
the retainers or bending any of the fuel
lines will make it difficult to reinstall the
fuel lines.
3. Disconnect the fuel return hose
(Figure 6-37, (2)) from the cylinder head.
4. Disconnect the hoses (Figure 6-37, (3)) from
the cold start device on the fuel injection pump.
ENGINE
0000080en
(2)
0001876
0000047en
6-47