GMS SERIES
OM-04386
PAGE E-7
MAINTENANCE AND REPAIR
In the instructions
which follow the
FRONT
is the
head assembly end of the pump and the
REAR
is
the drive (or backhead) end of the pump.
NOTE
It is strongly recommended that gaskets and O‐
rings be replaced whenever the pump is reas
sembled.
Preparing for Disassembly
The pump should be removed from the system pip
ing and drained for servicing. Close all valves in the
suction and discharge lines to isolate the pump.
Position drain pans and/or absorbant material un
der and around the pump suction and discharge
ports. Disconnect the suction and discharge hose/
piping.
Remove the hardware securing the pump to the
power source and separate the power source and
pump assembly. Retain all connection parts such
as shaft keys, etc.
Use a hoist and sling with sufficient capacity to
position the pump in a suitably sized drain pan or
surround the pump with absorbant material. Some
pumps are equipped with drain plugs in the head
and backhead. Remove the plug(s) and drain the
pump before proceeding with disassembly.
Pressure Relief Valve (10)
If the pump is equipped with a pressure relief valve
(10A), it can be mounted on either the head assem
bly (01A) or the housing assembly (04). Some
models are equipped with one of each. Take note
as to the direction in which the relief valve is
mounted. To remove either style, remove the caps
crews (B) securing the relief valve to the pump. The
O‐rings (10C) may remain in the head (01A) or in
the housing (04A). Remove and discard the O‐
rings. For relief valve maintenance, see
RELIEF
VALVE DISASSEMBLY
followed by
RELIEF
VALVE REASSEMBLY
at the end of this section.
Foot Bracket Kit (08, R Size Only)
Remove the hardware (B and D) securing the foot
bracket (08A) to the head (01A) and backhead
(06A).
Head/Idler Kit (01/02)
Disengage the hardware (B) and separate the
head jacket (if so equipped) and/or head assembly
(01A) from the housing (04A).
Use caution to prevent the idler assembly
from dropping off the idler pin; the idler
may be damaged if it falls on a hard sur
face.
Pull the head assembly (01A) from the housing as
sembly (04). Take care not to let the idler assembly
(02) slide off the idler pin (01AB). Remove and dis
card the gasket (01B).
Use caution when handling the idler (02A)
and the rotor shaft assembly (03A). These
parts have sharp edges which will grow
sharper with use.
NOTE
The idler bushing (02B) may be damaged during
removal. Do not remove the idler bushing unless re
placement is required.
Remove the assembled idler (02) and bushing
(02B) from the head assembly. Inspect the idler
bushing for excessive wear or scoring. If replace
ment is required, use an arbor (or hydraulic) press
and a suitably sized dowel to remove the idler
bushing (02B) from the idler (02A).
To remove the idler pin (01AB), lay the head as
sembly (01A) on an arbor (or hydraulic) press with
the idler pin (01AB) facing down and press the idler
pin (01AB) from the head (01AA).
Gland Removal (04N)
NOTE
Part of the seal assembly (5) will be removed with
the gland (04N). Check the
Parts List
furnished
with your pump to identify the seal, refer to
Seal Ap
pendix
,
Section F
for removal of the seal and re