Bosch 5312 - Circulation Pump; Motor Assembly

H
65
Circulation Pump / Motor Assembly
Fig. 16-6 Fig. 16-7
CIRCULATION PUMP / MOTOR REMOVAL:
Disconnect the four wire leads, then grasp the Circulation Motor and turn clockwise a quarter turn until
the Motor stops, Fig. 16-2. Now, remove the Motor / Rear Pump Assembly from the Front Pump
Housing, Fig. 16-3.
Note: The Front Pump Housing remains in place when the Motor is removed, Fig.16-3, item 1.
With the Motor / Rear Pump Assembly removed from the unit, separate the Motor from the Rear Pump
Assembly. To do so, first remove the Impeller by placing a block in the rear of the Motor and then turning
the Impeller counter-clockwise, then Fig 16-4.
The Rear Pump Assembly consists of four components, Fig. 16-5:
1. Rear Pump Housing. 3. Impeller.
2. Main Pump Seal. 4. Impeller Seal.
Each component can be replaced as an individual item.
TO INSTALL:
First, locate the Key Square on the Front Pump Housing, Fig. 16-6. Next, locate the Key Square Cut
Out on the Rear Pump Housing, Fig. 16-3, item 2.
When replacing the Pump / Motor make sure to line up the Key Square with the Key Square Cut Out.
Then bring the two pump halves together in the position shown in Fig. 16-2, and turn the Motor
clockwise until it stops, see Fig. 16-7.
Service note: The Impeller Seal Spring is compressed when the two halves of the Pump Assembly are
brought together. This will take a little force, so make sure to have a good grip on the
Sump as you compress the spring.
Now, reattach the wiring leads, test and check for leaks.