Tuesday, October 18, 2011

Repairing a Worn Vacuum Cleaner Rotary Brush Mount

Figure 1. Removing the damaged brush end retainer
We have this old vacuum cleaner that was formerly used by the custodial staff at the Broadmoor Hotel. And no, we didn't steal it, it was purchased fair and square at one of the auctions that the hotel holds every so often. It has done a good job for many years and I'm guessing the thing must be around 20 years old by now. It still sucks up crud, so what the heck—keep using it.

Unfortunately, it started making a humongous racket and leaving dark marks on the floor. After checking it out, it appeared the marks were made by the belt coming in contact with the floor and that was happening because one of the end retaining brackets for the rotary brush was damaged allowing the brush to wobble around and get out of position.

We like this machine and didn't want to get rid of it so I devised a fix. I imagine that similar problems develop on just about all makes of upright vacuums, so why not share my way of fixing it?

Vacuum Brush Mount Repair Procedure

Step 1. Remove the vacuum cleaner bottom cover, unhook the belt from the drive mechanism, and pull out the rotary brush.

Step 2. Figure 1 shows one of the end brackets that keeps the brush in position. The damaged part on the right side is removed using a chisel. It was supposed to be a mirror image of the left side, but it was all torn up and not keeping the brush end in place.

Figure 2. Rough cutting an aluminum retainer piece
Step 3. Fabricate a retainer piece out of aluminum stock by cutting it to size with a hacksaw and dressing it to final shape with a file (Figure 2). The retainer does not have to be fancy. I chose aluminum because it was handy, easy to work, and durable enough to last awhile. Wood or plastic would also do the job but wouldn't likely make for as long lasting a repair.

Step 4. After testing the retainer position and fit, drill a hole through the side of the vacuum (Figure 3), large enough in diameter to pass through whatever screw is to be used to fasten the retainer to the vacuum. I think it was a 10-32 machine screw in this case.

Figure 3. Drilling a mounting hole in the vacuum
Step 5. Holding the retainer in place, make a mark through the hole in the side of the vacuum to locate the place where the fastening screw will enter the retainer.

Step 6. Center punch the spot for the through hole on the retainer and drill a hole large enough to pass through whatever screw is to be used (Figure 4).

Step 7. Attach the retainer in position using a screw and a nut, but do not tighten it up all the way. If there is enough room, use a lock washer.

Step 8. Check the fit of the rotary brush and adjust the final position and alignment of the retainer for a snug fit. You should still be able to slide the end of the brush into the mount without difficulty.

Figure 4. Drilling a through hole in the retainer
Step 9. Tighten the nut on the mounting screw, and reassemble the machine. In this case, the brush ends held bearings that needed to be adjusted slightly before re-installation. This was done by simply tightening a screw on one end of the brush.

This vacuum is back in action and working great. It runs smooth and quiet and no more black marks are randomly applied to the floors. I foresee many more years of service for this machine. Not bad for a half hour of work using only parts and materials that were already on hand (See Figure 5 for how the part looks when finished).

Figure 5. The retainer in place doing its job