Finish Thompson UC (S/N 125040 and lower) - Manual (Page 15)

15
Replacement
1. Place impeller and impeller drive in an arbor press with the impeller side down.
2. Place rear sealing ring in the rear bore of impeller drive assembly and align anti-rotation tabs on the rear sealing
ring between the ribs in the impeller drives. (See figure 18B.)
3. Using a 3-inch diameter arbor, press in the ring. The sealing ring is fully seated when the bottom face of the ring
is in contact with each of the six ribs molded into impeller drive assembly bore. (See figure 18C.)
Rear Sealing Ring - For Pumps with Serial Numbers up to 119144-I13
The rear sealing ring (item 4C) is located in the rear bore of the impeller drive assembly
(item 4).
Removal
The rear sealing ring fits into the impeller drive with a snap fit. To remove the existing seal-
ing ring, cut a notch in the ring using a standard razor knife and remove. (See figure 18A.)
figure 18B figure 18C
figure 18A
Rear Sealing Ring - For Pumps with Serial Numbers 119145-I13 & Above
The rear sealing ring (item 4C) is located in the rear bore of the barrier assembly (item 6).
Removal
1. Place barrier (item 6) on a table with open side facing up.
2. Remove rear sealing ring by cutting it with a #18 straight edge X-Acto knife or similar
blade & gently cut through the ring. Once cut, simply spread open and remove the ring
from the barrier inner shaft boss. (See figure 18i.)
Replacement
1. Place barrier (item 6) in an arbor press with the open side facing up.
2. Place the rear sealing ring on the inner shaft boss of the barrier assembly, align the
two tabs so they will fit in between the ribs located in the bottom of the barrier.
(See figure 18ii.)
3. Gently press the ring into place evenly using an arbor press and a 2.68” (68 mm)
diameter tool. Note: this is the minimum inner diameter for the tool to fit over the
rear shaft boss. (See figures 18iii, 18iv, 18v.)
4. Ring is fully seated when it “snaps” into the machined groove on the boss, roughly 3/8”
(9.5 mm) from the top of the boss. (See figure 18vi.)
figure 18iii
figure 18ii
figure 18i
figure 18iv figure 18v figure 18vi