Yamaha F400A 2022 - Disassembling the Gear Pump Assembly; Checking the Gear Pump; Checking the Gear Pump Housing; Checking the Filter

PTT gear pump
9-59
Disassembling the gear pump
assembly
1. Remove:
• Valve lock screw “1”
TIP:
Before removing the valve lock screw “1”,
measure and write down the screw depth “a”.
Checking the gear pump
1. Check:
• Drive gear “a”
•Driven gear “b”
Damaged/worn → Replace the gear
pump assembly.
• Up-relief valve “c”
• Down-relief valve “d”
• Main valves “e”, “f”, “g”
Dirt/residue → Clean.
Checking the gear pump housing
1. Check:
• Gear pump housing
Corroded/cracked → Replace the PTT
unit.
Checking the filter
1. Check:
•Filters
Dirt/residue → Clean.
Assembling the gear pump assembly
Lubricate the parts using recommended fluid
during assembly.
When assembling the PTT unit, do not use
a rag. Otherwise, dust and particles could
get on the PTT unit components, causing
poor performance.
1. Install:
• Drive gear “a”
•Driven gear “b”
• O-rings “1”, “2”
• Main valve seals “3”
• E-clips “4”
•Down-main valve “5”
• Up-main valve “6”
• Springs “7”
•Pins “8”
1
1
a
c
a
b
d
e
e
g
f
New