The Kenwood BM450 is a real super bread maker, with convection and auto seed dispenser. The original bread pan developed a leak and I replaced it.But when the replacement bread pan started leaking after a few months, I had to find a repair as spares were not available in my area.
I used a Viton oil seal as a replacement for the bread pan shaft seal. I shall post a link from aliexpress.com from where I purchased it.
Step 1: Removing the Shaft and the Defective Seal.
This is the defective bread pan, and we have to extract the spindle by pushing it from the pan upper side.
Mine was so loose that it just fell out.
Once you have removed the spindle, keep it aside safely along with the 2 brass washers, impeller and cir clip. Now extract the old red rubber seal with a screwdriver or bent tip tool.
Remove a metal clip and another metal ring too.
Ensure you remove the rubber and everything from the cavity. Now clean the surroundings and the cavity thourougly.
Step 2: Measure the Hole Diameter With a Divider
Now you have to determine the hole size to order the oil seal. I arrived at 17 mm outer diameter . I
also verified with an ordinary rubber oil seal of 17 mm outer diameter that I had, just to make sure, before I ordered the Viton type. Unfortunately, the calipers will not fit here inside the pan.
Then measure the spindle diameter with a caliper.
The Kenwood spindle diameter is 8 mm. So the inner diameter of the seal should be 8mm.
Next determine the cavity depth. I arrived at 7mm.
So we need a Viton Oil Seal of 8mm (Inner Diameter) x 17mm (outer Diameter) x 7mm Width
Step 3: Order the Viton Oil Seal
Here is the AliExpress link to the shop I purchased from. I emailed the measurements to the email link of the shop, and the owner replied with a link that I bought from. I am posting screenshot of the item, but you will have to find the right item on the store or email the person.
Step 4: Fit the Seal Onto the Shaft and Re-assemble the Spindle
Clean the spindle throughly and fit the new Viton oil seal on it. Push this into the pan shaft hole from above, from the pan upper side.
Use a pvc pipe piece of diameter less than 8mm to tap it firmly inside with a mallet.
Ensure the oil seal is firmly seated. Do not use any glue.
Step 5: Fit the Impeller and Circlip From the Underside
Now refer to the assembly drawing, and fit the two brass washers, impeller and new stainless steel circlip.
Step 6: Final Leak Test
Fix the bread maker paddle onto the spindle. Fill with water.
Place some paper under the pan.
Keep for an hour and check for leakage of water on the paper.
Turn the paddle manually for some time, and test for water leakage.
Only if integrity of the seal is perfect, one may proceed with bread making in the machine.