Finish Thompson Little Cooler - Manual (Page 11)

11
Pump and motor disassembly:
1. Set the pump and motor assembly onto the motor fan cover so that the pump is facing
upright on the workbench.
2. Remove the five socket-head bolts that hold on the pump’s housing and remove the pump
housing. The nuts for the bolts are recessed into the tabs of the motor adapter. Also
remove the housing o-ring.
IMPORTANT: Take note of the orientation of the pump’s discharge (where the elbow is
attached) to allow proper reassembly after repairs.
3. Turn the pump’s impeller until one pair of the impeller shaft’s setscrews becomes visible
through the slots in the motor adapter. Loosen that pair of setscrews, and then turn the
impeller again to locate and loosen the second pair of setscrews.
4. Pull the impeller and impeller shaft away from the motor’s shaft (an assembly of the
impeller, impeller shaft, housing cover, and seal will be removed together).
NOTE: The impeller shaft may be difficult to pull loose from the motor. Attempt to pry on the
base of the impeller shaft with a flat screwdriver through the slots in the motor adapter.
Take care to not damage any pump components while prying.
5. Loosen the four socket-head bolts to remove the motor adapter and motor from the motor
mounting plate.
6. Inspect all parts and replace any parts that appear worn, melted, or corroded.
Pump and motor reassembly:
1. Bolt the motor and motor adapter to the motor mounting plate using the four socket-head
bolts.
2. Coat the motor’s shaft with an anti-seize compound. Install the impeller, impeller shaft,
housing cover, and seal assembly onto the motor shaft. Do NOT tighten the impeller
shaft’s setscrews at this time.
3. Place the housing o-ring into position on the housing cover. Bolt the housing cover into
position with the pump’s discharge in the same position as it was originally. The nuts for
the bolts will insert into the tabs of the motor adapter.
4. Set the gap between the impeller vanes and the inside of the housing cover to the proper
tolerance. Insert a .020” feeler gage into the suction of the pump’s housing (remove the
suction screen if so equipped). Position the feeler gage on top of one of the impeller’s
vanes. Pry up on the base of the impeller’s shaft (use a flat screwdriver through the slot in
the motor adapter) until the feeler gage is sandwiched between the vane and the housing.
Tighten the four setscrews in the impeller shaft, and remove the feeler gage. Re-insert the
suction screen (if equipped).
IMPORTANT: It is critical for performance that the gap between the impeller’s vanes and the
inside of the housing cover is set to the proper distance. A gap of .020” +/- .005 is
required.