Yanmar MP series Service Manual page 60

FUEL INJECTION PUMP
Hydraulic Head
1. Mark the positions of the fuel inlet
(Figure 5-22, (1)) and return fittings
(Figure 5-22, (2)) and remove.
Figure 5-22
IMPORTANT
The delivery valve has many parts that are
very small. Do not drop or lose the check
valve.
2. Remove each of the delivery valve housings
valves and gaskets (Figure 5-23).
0001 181
Figure 5-23
Note: Be careful not to lose the secondary
check balls during disassembly of the
delivery valves.
3. Disassemble each delivery valve (Figure 5-24).
Note: Keep and identify all parts in order during
disassembly. Do not mix valve parts. If
reused, each valve must be reassembled
with the original parts and reinstalled in
the original port.
1. Valve Seat
2. Return Spring
3. Secondary Check Ball Spring Seat
4. Secondary Check Ball
5. Delivery Valve
6. Primary Spring
7. Delivery Valve Housing
Figure 5-24
4. Remove the distribution shaft plug
(Figure 5-25, (I)), and O-ring
(Figure 5-25, (2)).
GO03552b
Figure 5-25
MP Series Service Manual
YANMAR,