YAMADA NDP-5 series Maintenance Manual

9
6. Throat bearing and Pilot valve
6.1 Removal
▪ Remove the diaphragm and center rod (see [5.1 Removal]).
▪ Remove the 12 retainer bolts from the air chamber, and remove
the air chamber. [Fig.6.1]
▪ Draw out the pilot valve and valve seat. [Fig.6.2]
▪ Draw out the throat bearing. [Fig.6.2]
▪ Remove the packing from the throat bearing. [Fig.6.3]
6.2 Inspection
▪ Throat bearing [Fig.6.4]
Measure the inside diameter, and if it is outside the usable
range, replace the throat bearing
Usable range of throat bearing
ø0.9859 ~ ø0.9902 in {ø25.04~ ø25.15 mm}
▪ O ring, Packing
If the O ring is worn out or cracked, replace it.
▪ Pilot valve
If the pilot valve is worn out or cracked, replace it.
6.3 Installation
For installation, see [Exploded View] on the separate sheet and install in the reverse order of disassembly.
Tightening torque for air chamber retainer bolts
15 ft-Ibf {20 N-m}
<NOTE>
▪ Make sure there is no dust on the seal surface and the seal is
not damaged.
▪ Apply grease to packing.

YAMADA NDP-5 series Specifications

General

Brand	YAMADA
Model	NDP-5 series
Category	Water Pump
Language	English