Upper Seal
1.
To remove and replace the upper mechanical seal, the base, impeller, lower mechanical seal, and volute
must be removed first. Drain the seal oil from the housing by removing pipe plug.
2.
The rotating carbon ring and stainless steel spring are held in place by a snap ring and washer. Remove
these.
3.
Remove the four hex head stator bolts and lift the stator. A screwdriver can be inserted under the stator
shell in order to remove the stator.
4.
Bump the end of the shaft with a plastic hammer. This will push the rotating half of the mechanical seal
from the shaft and also push the lower bearing from the seal plate. Now remove the shaft, rotor, and
bearing assembly from the seal plate.
5.
If water was found in the oil, the rotating and stationary halves of the mechanical seal must be replaced.
Remove the stationary seal half by inserting a screwdriver into seal plate from the top and tapping lightly
with a hammer.
6.
Turning the bearing by hand: if it feels rough when turned or looks rusted, it should be replaced. Obtain a
bearing puller to remove the bearing. If a puller cannot be replaced over the bearing, remove the outer face
by cracking in a vise. Now the outer face and balls can be removed, allowing the inner face to be pulled.
Reassembly
1.
Thoroughly clean the seal plate, particularly the seal and bearing pockets. All sand and dirt must be removed.
2.
If the stationary seal half was removed, use a plastic pusher to press it into the housing. Make sure the rubber
ring goes in first. Do not use any sharp objects that may damage the seal.
3.
When installing a replacement bearing, press only on the inner face and make sure the bearing is flush against
the snap ring. If a press is not available, the bearing can be tapped onto the shaft using a sleeve that bears only
on the inner face. Pressing on the outer face will ruin the bearing.
4.
Push the shaft, rotor and ball bearing assembly into the seal plate, being careful not to chip the ceramic of the
stationary seal half.
5.
Replace the stator if it is visibly burned or if the ground resistance test or the winding resistance test has failed.
Note that the replacement stator must be of the same manufacturer as the existing rotor, or vice versa. Replace
the four stator bolts.
6.
Remove the old O-ring regardless of condition, and replace. Place the new O-ring over the seal plate shoulder.
Do not roll it. If twisted water may enter chamber and cause failure.
7.
Clean the motor housing thoroughly, then position it onto the seal plate.
8.
Press the rotating seal half onto the shaft with the rubber ring facing the impeller.
Caution: Mixing old and new seal parts will cause immediate seal failure. When replacing seal, replace both
the rotating and the stationary seal halves.
9.
Reassemble the lower seal as described.
10.
Add a drop of Locktite 222 to the shaft and screw the impeller on hand-tight. The impeller will force the
rotating seal half into position.
11.
Set the seal housing and motor housing assembly into the volute case and secure with four hex head screws.
12.
To replace the power cord on single phase pumps as determined, first slip the stator lead wires through the
holes in the wire seal assembly. Coat the cord grip threads with pipe dope or apply Teflon tape and screw the
new power cord assembly inot the motor housing. Secure wires together. Do not tape leads together as the hot
oil will deteriorate the tape and cause motor failure.
13.
Before filling the motor housing with oil, an air test should be performed. Apply 7 to 8 pounds of air pressure
in the ¼” NPT tap on the top of the motor cover and seal chamber.
Note: Too much pressure will damage the seal.
Then submerge the pump in water and check for leaks. If a leak occurs, isolate where it is coming from and
correct the sealing part. If there are no leaks, fill the motor and seal housing with high grade transformer oil,
such as Sohio Factopure SE40 or equivalent, to at least one inch below top of housing. Do not fill the motor
housing completely - allow air space for expansion. Replace oil plugs. Turn pump on side and fill seal
chamber to 1” from top. Replace plug and stand pump up.
