HIGHLAND RIDGE OPEN RANGE 308BHS - Slide-Out Seal Replacement

HIGHLAND RIDGE OPEN RANGE 308BHS – Slide-Out Seal Replacement

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Complete repair guide for the HIGHLAND RIDGE OPEN RANGE 308BHS – Slide-Out Seal Replacement.

Parts & Tools You’ll Need

Step 1: Diagnose Seal Damage and Prepare Workspace

Begin by manually extending and retracting the slide-out room several times while visually inspecting the perimeter seals for cracks, tears, peeling, or hardening. Pay particular attention to the top wiper seal and bottom compression bulb seal where water intrusion most commonly occurs. Park the trailer on level ground, fully retract the slide-out, and set up your workspace with adequate lighting and ventilation. Gather all necessary tools including the Plastic Trim Pry Tool Set, cleaning supplies, and your replacement seal materials to ensure you won’t interrupt the work midway.

Step 2: Remove Old Seal Materials Completely

Using the plastic pry tools, carefully lift and separate the existing D-Seal from the slide-out frame starting at a corner and working your way around the entire perimeter. Gently peel away any remaining adhesive residue using the pry tool, working slowly to avoid gouging the aluminum frame or sidewall material. Once the old seals are removed, use rubbing alcohol on a clean cloth to dissolve and wipe away all remaining adhesive from both the frame and the mating surface. Inspect the frame for any cracks or damage; minor surface corrosion can be lightly sanded with 220-grit sandpaper and wiped clean before proceeding.

Step 3: Install Top Wiper Seal Assembly

Apply a continuous 1/8-inch bead of 3M Super Weatherstrip Adhesive along the top frame channel where the Slide-Out Top Wiper Seal will seat. Carefully position the wiper seal starting at one corner and press firmly as you work around the entire top perimeter, maintaining consistent pressure to ensure full contact. For the 308BHS model, the top run typically measures approximately 13-14 feet; use the Corner Seal Connector kit at each 90-degree angle to create a professional, continuous seal. Allow the adhesive to set for 15 minutes before proceeding to the next seal component.

Step 4: Apply Bottom Compression Bulb Seal

Run a 1/8-inch adhesive bead along the bottom frame channel and position the Slide-Out Compression Bottom Bulb Seal, pressing it firmly into place as you progress around the lower perimeter. This bulb seal compresses when the slide-out is retracted, creating the watertight seal at the bottom, so ensure it’s seated evenly without gaps or kinks. Use the Corner Seal Connector kit at bottom corners, overlapping the seal material by 1/2 inch and securing with additional adhesive. The bottom seal run on the 308BHS is approximately 13-14 feet; verify that the seal extends fully into all corner connections before allowing adhesive to cure.

Step 5: Install AP Products D-Seal on Frame Edges

Apply 3M Super Weatherstrip Adhesive to the outer edges of the slide-out frame where the AP Products D-Seal will attach, working one side at a time. Press the D-Seal firmly onto the frame, ensuring it wraps around all edges smoothly without twists or pressure gaps. The D-Seal on the 308BHS typically runs 8-9 feet on the long sides and 6-7 feet on the short sides; mitered corners using the Corner Seal Connector kit create a professional appearance and prevent water from entering at joints. Allow a minimum of 30 minutes curing time before retracting or extending the slide-out.

Step 6: Seal Joints with Structural Silicone

Apply a continuous bead of clear Structural Silicone Sealant along all seams where the D-Seal, wiper seal, and bottom bulb seal meet, particularly at all corner connections. Use a silicone-smoothing tool or wet finger to create a smooth, concave profile that sheds water effectively and creates a professional finish. Pay extra attention to the seams at corner connections where the Corner Seal Connector kits are positioned, as these are vulnerable points for water infiltration. Allow the silicone to cure for a full 24 hours before exposing the seals to water or weather.

Step 7: Test Seals and Verify Water-Tightness

After 24 hours cure time, manually extend and retract the slide-out room slowly 3-4 times, checking that all seals compress and recover smoothly without bunching or separating from the frame. Visually inspect the entire perimeter for gaps, tears, or improperly seated sections, paying special attention to corners and transitions. Perform a water test by using a garden hose on low pressure to spray water directly onto all seal seams and corners while the slide-out is partially extended, checking for any water dripping or entering the interior. Apply Rubber Seal Lubricant / Protectant to all seals following manufacturer instructions to extend their lifespan and maintain flexibility.