How to Replace the O-Rings on a Makita Finishing Sander

If raised grains and elbow strains are sanding away your patience, it's time to face the fix. Whether you are a sanding professional or a seasonal sander, eReplacementParts.com provides the parts, procedures and facts you need to fearlessly fix what fails you.

The pad o-rings dampen vibration between the metal posts and the plastic components inside the sander. O-rings should be inspected and replaced (as-needed) whenever the sander is disassembled for service. If any of the o-rings on your Makita finishing sander are missing, compressed or torn, this article will show you how to quickly and easily replace them.

Let's get started.   REMOVING THE O-RINGS [top] 1. Remove the sanding pad from the base assembly.

a. Remove the four retaining screws from the sanding pad.

b. Remove the sanding pad from the base plate.

    2. Remove the base assembly from the sander.

a. Insert a standard screwdriver through the opening in the center of the base plate (alongside the retaining screw). This will prevent the motor shaft from spinning while you remove the screw.

b. Remove the retaining screw.

c. Remove the base assembly from the sander.

    3. Remove the o-ring(s).

a. Remove the metal posts from the base assembly.

b. Use a pick or small screwdriver to remove the o-ring(s).

    INSTALLING THE NEW O-RINGS [top] 4. Install the o-ring(s).

a. Install the new o-rings into the openings on the base assembly (or motor housing).

b. Use your finger (or a small screwdriver) to press the o-rings firmly into place.

c. Inspect and replace the remaining rings as necessary (there are four on the base, and four on the top half of the unit).

    REASSEMBLING THE UNIT [top]  5. Reinstall the posts.

a. Install the four metal posts into the base assembly.

b. Press firmly on each post to ensure that it is seated within the o-ring.

     6. Reinstall the base assembly.

a. Ensure that the four metal posts are firmly seated into the corresponding o-rings within the base assembly.

b. Verify that the remaining o-rings are seated in the top half of the motor assembly (image shows 2 of 4).

c. Align the holes on motor assembly with the four metal posts (on the base).

d. Press down firmly on the motor assembly to join the two halves.

e. Verify that the metal posts have securely engaged the o-rings on both halves of the unit.

f. Install the counter-weight onto the center post.

g. Install the retaining screw until it is hand-tight.

h. Bind the motor by inserting a screwdriver through the opening in the center of the base plate. This will prevent the shaft from spinning as the screw is tightened.

i. Secure the retaining screw.

    7. Reinstall the sanding pad.

a. Align the sanding pad with the holes on the base assembly.

b. Secure the sanding pad with the screws.

Sanding can be a demanding task. But you don't have to rough-up your accountant to smooth-out your countertops. As you just learned, repairing your own power tools is simple when you follow our step-by-step guides. Not only did you expand sander functionality at a fraction of the cost of replacement; you have taken the edge off all future repairs. Find your next fix here.   [top]