Applies to: Chevy C10, C20, K10, K20 (1960-1972, 1973-1987 Squarebody), Ford F-100, F-150, F-250 (1953-1996), GMC Trucks, and most classic American pickups.
Understanding Your Seal Type: Push-On vs. Glue-On
Before beginning installation, identify which type of door seal you have—this determines your installation method:
| Seal Type | Identification | Installation Method |
|---|---|---|
| Push-On (Press-On) | Features a metal or plastic pinch welt/channel along the back edge; often has pre-formed corners | Presses directly onto the door opening flange—no adhesive required |
| Glue-On | Flat back surface with no clips or pinch welt; may have molded corners | Requires 3M Black Weatherstrip Adhesive (GL-11) |
| Clip-On with Adhesive | Has metal clips or fastener holes at intervals | Attach clips to body, then apply adhesive between clips to prevent gapping |
💡 Pro Tip: If your seal has clips, you still need adhesive between the clip points. This prevents the seal from pulling away and creating air/water leaks.
What You'll Need
- New door weatherstrip seal
- 3M Black Weatherstrip Adhesive (GL-11) (for glue-on types)
- 7-Piece Trim & Pry Tool Set (GL-30)
- Nitrile Gloves (GL-10)
- Wax and grease remover (or isopropyl alcohol)
- Clean lint-free rags
- Plastic scraper or putty knife
- Heat gun (optional—for stubborn old adhesive)
Save time and money: Our Complete Installation Kit (GLK-1) includes adhesive, gloves, and essential tools in one package.
Step 1: Remove the Old Seal
- Open the door fully and locate all attachment points.
- For push-on seals: Grip the rubber firmly and pull it away from the door opening flange. Work around the perimeter. Use a trim tool from the GL-30 set to help release stubborn sections without damaging paint.
- For glue-on seals: Peel the rubber away slowly. If adhesive remains bonded, use a plastic scraper. For stubborn residue, apply heat with a heat gun (keep moving—don't scorch the paint).
- Remove all clips if present. Note their locations for reinstallation.
Step 2: Clean the Mounting Surface (Critical!)
⚠️ WARNING: Skipping this step is the #1 cause of seal failure.
- Scrape off all old adhesive residue with a plastic scraper.
- Wipe the entire door opening flange with wax and grease remover or isopropyl alcohol.
- Allow the surface to dry completely (5-10 minutes minimum).
- The metal should be clean, dry, and free of oils before proceeding.
Step 3: Dry-Fit the New Seal (Do This First!)
Never apply adhesive before dry-fitting. This is a common mistake.
- Identify orientation: If your seal has a Red Dot, it goes on the Driver (Left) side. A Green Dot indicates the Passenger (Right) side.
- Locate the molded corners: Most truck door seals have pre-formed corners that must align with the door frame corners. Position these first.
- Start at the top center of the door opening and work your way down both sides.
- Ends meet at the bottom: The splice point should be at the bottom center of the door opening (the rocker panel area), where it's least visible and least likely to leak.
- Check that the seal sits uniformly with no gaps, twists, or bunching.
Step 4: Install the Seal
For Push-On / Press-On Seals (Common on 1967-1972 C10/GMC):
- Starting at the top center, align the pinch welt over the door opening flange.
- Press firmly along the entire length, ensuring the channel fully grips the metal flange.
- Work the corners carefully—don't stretch the rubber. The molded corners should seat naturally.
- Continue down both sides until the ends meet at the bottom.
- No adhesive is needed, but you may apply small dabs of 3M adhesive (GL-11) at the splice point for extra security.
For Glue-On Seals (Common on 1973-1987 Squarebody, 1973-1979 Ford F-Series):
- Apply adhesive to the body, not the seal. Apply a thin, even bead of 3M Black Weatherstrip Adhesive (GL-11) to the door opening flange.
- Spread the adhesive with a small brush or popsicle stick into a thin layer. Less is more—thick globs won't cure properly.
- Let it tack up (3-5 minutes until slightly tacky to touch).
- Starting at the top, press the seal firmly into position, working down both sides.
- Press and hold each section for a few seconds to ensure good contact.
- Allow 24 hours cure time before closing the door firmly.
For Seals with Clips:
- Install the clips first, aligning them with the factory holes in the door jamb.
- Snap or screw the seal's attachment points onto the clips.
- Apply small dots of adhesive between each clip to prevent the seal from pulling away from the body.
Step 5: What to Expect After Installation
⚠️ The "Break-In Period" (Important!)
Your door may be hard to close at first—this is normal.
Metro SUPERsoft rubber is intentionally manufactured slightly larger than the original compressed seal to create a superior air and water barrier. Here's what happens:
- Days 1-7: Doors may require extra effort to close. The latch may feel stiff.
- Days 7-14: The seal begins to compress and conform to your door.
- After 2-3 weeks: Doors should close with normal effort.
💡 Speed Up Break-In (Optional): Some restorers gently warm the seal with a heat gun on LOW setting while the door is closed. This helps the rubber "memorize" its shape faster. Use caution—don't overheat.
Do NOT trim the seal if it feels too thick. Give it time. The rubber will compress.
Troubleshooting
| Problem | Cause | Solution |
|---|---|---|
| Door won't latch | Seal still breaking in | Wait 1-2 weeks; optionally use heat gun method |
| Seal pulls away from body | Insufficient adhesive or poor surface prep | Remove, clean thoroughly, reapply with fresh adhesive |
| Water leaks at corners | Corners not properly seated | Re-seat corners; add adhesive at corner joints |
| Air whistle / wind noise | Gap in seal or splice point | Check splice alignment at bottom; add adhesive if needed |
| Seal bunching or twisted | Incorrect starting position | Remove and reinstall; ensure molded corners align first |
Vehicle-Specific Notes
Chevy/GMC C10, K10 (1967-1972):
- Most commonly use push-on style seals with pinch welt.
- Factory seals have molded corners—don't stretch them.
Chevy/GMC Squarebody (1973-1987):
- Often glue-on style or combination clip-and-glue.
- Some models have screws at top and bottom with adhesive in between.
Ford F-100, F-150, F-250 (1973-1979 "Dentside"):
- Primarily glue-on style.
- Start at the top center, work down—ends meet at the bottom center.
- Use 3M adhesive (GL-11) applied to the body, not the seal.
Ford F-150 (1980-1996 "Bullnose" & "OBS"):
- Glue-on style continues through this era.
- Later models may have integrated clips at corners.
Need the right seal for your truck? Browse our complete truck door seal selection by year, make, and model.
Jan 9, 2026