Harley Davidson Hydraulic Backrest Installation Instructions

Install a Backrest on Your Harley Davidson for a Comfortable Ride

Most of the modern-day era Harley Davidson motorcycles are fully loaded with accessories aimed to create a luxurious experience, including satellite radio, heated grip handles and preinstalled hydraulic backrests. If your Harley Davidson does not come equipped with these accessories, then you can install one yourself. For instance, a hydraulic backrest requires about an hour for one person to install. Adding a hydraulic backrest can help minimize back pain while traveling long distances.


1. Remove the saddle-bag covers from each side of the motorcycle. Depending on the model year, there will be one (1991-present) or two (1988-1990) mounting bolts. Remove the mounting bolts with an adjustable wrench.

2. Refer to your service manual to uninstall the seat assembly. Flip the seat assembly over to expose the mounting bolts. Remove the mounting bolts secured to the seat assembly with an adjustable wrench. Remove the seat and place it off to the side to prevent potential damage. Remove and discard the two mounting bolts attached to the hand rail assembly plate and rear fender with an open-end wrench.

3. Gather two 5/16-inch to 24-inch-by-7/18-inch locking bolts for model years 1998 and older. Install one flat washer and lock washer on each locking bolt, then finger-tighten snugly. Skip this step for model year 1999.

4. Locate the backrest mounting bracket with the locking tab in front of the motorcycle, then slide it over the hand rail mounting plate guideposts. Flip the mounting bracket over to accommodate the backrest. Thread one lock nut and plastic washer over the Allen screw, then finger-tighten snugly. Thread one Allen screw through the back of the pad, then tighten it securely with an Allen wrench.

5. Position a 1 1/8-inch OD washer under the backrest mounting bracket, then secure it with 5/16-inch to 18-inch-by-7/8-inch locking bolts and washers for all 1997 and 1998 models without a handrail. Tighten the assembly with an adjustable wrench.

6. Thread the removed locking bolts through the backrest mounting bracket and hand rail plate guideposts. Torque the locking bolts to 19 foot-pounds with a torque wrench for model years 1998 and older.

7. Remove the plastic cap and locking nut from the stud using your hands. Do not remove the plastic washer, otherwise the stud plate will fall out-of-place. Secure the backrest mounting bracket to the stud plate with the stud plate locking nut for model years 1998 to 2008 with an adjustable wrench. Slip a small piece of battery tube through the fender hole if the stud plate falls out-of-place. Secure the tube to one of the studs, then finger-tighten. Move the tube up, then position the stud back into place with your hands.

8. Remove the lock bolt, nut and washer from the rear fender and frame member for model years 1996 and older with an adjustable wrench. Secure the backrest mounting bracket support to the frame member using the same lock bolt, nut and washer previously removed with an adjustable wrench.

9. Slide the clip nut over the frame cross member center hole, which lies behind the battery for model years 1997 to 2008. Secure the bracket support to the frame cross member by installing a 1/4 to 20-by-1/2-inch locking through the bracket support hole. Thread the locking bolt through the clip nut, then tighten the locking bolt securely with an adjustable wrench.

10. Flip the bracket support over to accommodate the backrest. Twist the bracket support up on the backrest mounting bracket. Thread a flange bolt and nut through the backrest mounting bracket, then tighten it securely with a flange wrench. Reinstall the seat assembly and saddlebag covers.

11. Keep the slit located between the rider and passenger seat open. Apply pressure to the backrest rods and spring located on the rider backrest. Install rods into the backrest bracket. Align the forward position of the backrest pad. Adjust the set screw threaded through the eyelet opening at the back of the pad with a 3/16-inch hex wrench. Do not remove the screw completely because it will be difficult to reinstall.