Gardner Denver Oberdorfer 800B Guide

315-437-0361 or 800-448-1668 Fax: [phone] web: www.oberdorfer-pumps.com
1. Remove Pump Cover.
This exposes the centrifugal impeller.
2. Remove Pump Impeller
(SEE FIGURE 1) The impeller is threaded onto the shaft.
Unscrew impeller from shaft by shocking with screwdriver
and hammer. Note that all impellers unscrew in the same
direction as the pump rotates. Thus, the impeller unscrews
counter clockwise when facing the open end of the pump.
However, Model 800B has left hand threads and unscrews
clockwise.
Usually the shock force alone is sufficient to
unscrew the impeller. In extreme cases it may be necessary to
restrain the shaft. For pedestal centrifugal pumps, the exposed
drive end of the shaft can be clamped in a vise and restrained
accordingly. For pumps close coupled mounted to electric
motors, restrain the shaft via the screwdriver slot in opposite
end of motor shaft. (SEE FIGURE 2) The impeller hub exten-
sion may also be gripped with a pipe wrench, channel lock, or
vise grip to loosen and remove it.
If motor does not have a screwdriver slot in opposite
end of shaft, restrain motor shaft by inserting screwdriver
through air openings in motor body to bear against fan or
cooling air projections of motor armature. Exercise care not
to damage motor fan or armature.
3. Remove Pump Body (or pump casting containing the
seal)On some models, the pump body is clamped to motor
adapter by a single bolt. Loosen nut and slide pump body off.
On other models, the seal is contained in the pedestal
bracket or adapter to the motor.
Centrifugal Pumps:
Seal Replacement Instructions
The following instructions are general. Although the illustrations may not depict the specific centrifugal
pump model you are concerned with, the seal components are similar for all centrifugal pumps.
FIGURE 1
FIGURE 2
*Teflon® is a registered trademark of DuPont.
Permatex® and Locktite® are registered trademarks of Locktite Corporation.

4. Press Seal from Pump Body or from the Pump
Casting Containing the Seal
(SEE FIGURE 3) The seal is a press fit in the pump body
or adapter. To press out, place body flange down on flat sur-
face exposing motor or bracket end of seal. Press seal
through into impeller chamber - DO NOT attempt to press in
other direction as seal has a seating flange. Clean the bore in
the pump body from which seal was removed. Remove all
hardened residue. Do not gouge or damage seal bore. (SEE
FIGURE 4) On some pedestal pump models (70P & 800B),
it is not possible to press out the seal without first pressing
out the shaft and bearing assembly. In such cases, it is possi-
ble to collapse and pry out the seal while leaving the shaft
and bearing assembly in position.
5. Press New Seal into Pump Body
( SEE FIGURE 5) Coat bore with Permatex #2®, Teflon®
paste, Locktite 620®, or equivalent sealer to press-in. Use
bushing type pusher to press and press only on metal flange
of seal DO NOT press on spring loaded carbon face. DO
NOT damage or scratch lapped carbon face.A scratched sur-
face will cause seal to leak.
6. Remove Seal Wear Face from Impeller
(SEE FIGURE 6) If lapped wear face projects above
impeller, use pliers to pry out. If wear face does not project,
use knife or sharp instrument to pry out.
7. Install New Seal Wear Face
Coat wear face (and seal seat) with liquid soap and push
into impeller chamber with finger pressure. DO NOT damage
or scratch wear face surface.
8. Reinstall Pump Parts
Reinstall pump parts to motor adapter or to motor and
pedestal bracket or adapter in reverse order as follows:
1. Slide pump body on motor adapter or bolt
pedestal bracket or adapter to motor.
2. Thread impeller onto shaft. Be sure to replace any
spacer shims used originally for impeller
positioning.
3. Clamp pump body to motor adapter by single
draw down bolt. A rotating clearance should remain
between body or cover and impeller.
4. Reinstall gasket, or o-ring and pump cover.
9. Check for Impeller Interference
Check that the impeller does not interfere with pump
body or cover by rotating impeller by hand or jogging the
motor. Metallic noise is a sign of interference. To eliminate
interference noise, reposition the impeller to better center it
in the body chamber and provide rotating clearance. Do this
by adding or removing spacer shims onto motor shaft.
10. Impeller Shimming
Since jet pump motor shaft projections can vary, pump
heads are provided with impeller shim kits. In general, an air
gap of 0.010” to 0.015” is recommended between the rear
shroud of the impeller and the motor adapter face. Once the
pump casing is mounted, check to be sure that the impeller is
not rubbing against the casing. Adjust shimming as needed.
315-437-0361 or 800-448-1668 Fax: [phone] web: www.oberdorfer-pumps.com
FIGURE 4
FIGURE 5
FIGURE 6
FIGURE 3
rev. 02/08