How to Replace C4 Corvette Outer Window Seals With Ease

Doors of Perception

John Gilbert Oct 14, 2015

1 C4 Vette Outer Window Seal New Seal Installed
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There’s an old saying journeymen car painters pass on to the new kids entering the trade, and that’s, if nothing else, make sure the driver door and the top of the hood look good. That’s a bit of advice I’d like to share with anyone that owns a 1984-’96 C4 Corvette. Whether you’re going to sell the car or you intend to cherish it forever, make sure the outer window seals are near mint or your C4 will be perceived to be in crummy overall condition.

A case in point is the triple-black 1990 Z51 Corvette featured in this article. I bought the car a year ago when I decided I needed a dependable economy car to take the monetary sting out of daily-driving my ’05 GMC Sierra. I found the 69,000-mile Z51 listed on Santa Barbara’s Craigslist 125 miles from my home; and the price was right. I had the seller email me a photo of the SPID (service parts identification sticker located inside console lid) and discovered the original owner checked all the right boxes when he ordered the car new from the dealer. I learned every performance option found on a 1990 RPO ZR1 or RPO B2K Callaway was on this car.

Anxious and armed with an envelope full of cash, I fled Orange County before sunrise. I’ll never forget my first impression of the black Z51 as I pulled into the driveway, it had a strong presence, as all Corvettes do, but its gap-toothed cracked outer window seals made it look bad. I took this as a summation of the car’s overall condition and I was beginning to lose interest fast. I wasn’t all that excited to test drive the Z51, but the owner insisted. I headed north from his beachfront home up the coast through the lush foliage of Hope Ranch and that was all it took to decide I was going to buy this car.

I’m not real adept when it comes time to chisel an owner down on the price of a used car, so it came in real handy that the two of us were standing next to the shabby window seals while we were discussing price. There’s no question in my mind the bad outer window seals undermined the seller’s perceived value of his car, and that’s the reason I got a good deal on a really great car.

Beyond cosmetic considerations, there’s numerous operational benefits to be gained by renewing a C4 Corvette’s outer window seals. The gaps left by missing chunks of rotted outer window seals allow dirt and water to enter inside the door’s workings, creating wind noise and potentially causing power window and electrical switch failures. Rusted window mechanisms can jam and prevent proper function.

For the person that likes to keep their Corvette nicely detailed plus add a few upgrades while they’re doing repair work, replacing the outer window seals presents a good opportunity to super detail the door panels, plus install sound and heat proofing.

2 C4 Vette Outer Window Seal Old Before Replacement

01. Here’s what the factory original outer window seals looked like before replacement. Broken outer window seals allow water and dirt to enter inside the door and cause expensive electrical and/or mechanical damage.

3 C4 Vette Outer Window Seal Disconnect Battery

02. The first step is to lower both side door windows and then disconnect the negative post of the battery.

4 C4 Vette Outer Window Seal Door Panel Screws

03. The door panels must come off in order to replace the outer window seals. All Phillips screws that are visible in the door panels must be removed.

5 C4 Vette Outer Window Seal Lower Trim Panel Screws

04. Notice how water entering and collecting inside the door caused the door panel screws to rust.

6 C4 Vette Outer Window Seal Tag And Bag

05. Tagging where the screws came from and storing them in a sealed bag is a good practice to ensure original hardware is not misplaced.

7 C4 Vette Outer Window Seal Power Mirror Plug

06. The power mirror control switch connector plug is released by unhooking (pull tab outward) at the switch.

8 C4 Vette Outer Window Seal Power Window Plug

07. To disconnect the power window switch, a special tool was homemade from a cotter key to release the two locking tabs simultaneously.

9 C4 Vette Outer Window Seal Homemade Plug Disconnect Tool

08. Twisting the special homemade tool upward opened the two locking tabs enough to separate the plug from the switch.

10 C4 Vette Outer Window Seal Remove Courtesy Light

09. To remove the courtesy light from the door panel, there are two tabs on top of the light that need to be pressed down. Then the top of the light comes out first.

11 C4 Vette Outer Window Seal Screw Behind Light

10. Behind the courtesy light is a Phillips screw that must be removed.

12 C4 Vette Outer Window Seal Unhook Doorlock Knob

11. To access the Phillips screw behind the door lock knob, a hook tool is used to pull the lock knob forward.

13 C4 Vette Outer Window Seal Remove Lock Knob

12. The door lock knob pulls outward to release it from the lock rod.

14 C4 Vette Outer Window Seal Screw Behind Lock Rod

13. The hook tool was used to pull the lock rod down and forward to allow access to remove the hidden Phillips screw.

15 C4 Vette Outer Window Seal Pull Door Handle

14. The inside door handle is pulled outward (same as opening the door) to release the lock panel from the door panel.

16 C4 Vette Outer Window Seal Remove Handle Surround

15. The door lock panel pulls outward to remove, but does not need to be removed completely from the wiring.

17 C4 Vette Outer Window Seal Rear Hatch Plug

16. The rear hatch switch (adjacent the inside door lock mechanism at rear) must be disconnected. Unplug by opening the locking tab.

18 C4 Vette Outer Window Seal Door Liner

17. To replace the outer window seals, this clear plastic liner does not need to be removed, but I chose to upgrade to the later year model C4 door panel insulators from Corvette Central (PN 284084).

19 C4 Vette Outer Window Seal Remove Clip

18. The two clips holding the liner only need to come forward enough to unwrap the clear plastic liner from the clips.

20 C4 Vette Outer Window Seal Door Panel Off

19. While the clear plastic liner was removed, I used the access to blow out and vacuum dirt and broken chunks of the original outer seal left inside the door.

21 C4 Vette Outer Window Seal Loosen Weatherstrip

20. There are three pop rivets that must be drilled out to remove the old outer window seal. To gain access to the rivets, the door weatherstripping must be moved out of the way.

22 C4 Vette Outer Window Seal Protect Rubber W Tape

21. After removing the two 7mm-headed bolts and carefully peeling the weatherstrip back, blue tape was used to hold the weatherstrip clear of the drill.

23 C4 Vette Outer Window Seal Insulator Barrier

22. Notice how nicely the new Corvette Central door panel insulator conforms to the door with heavier material.

24 C4 Vette Outer Window Seal Eastwood Restore Screws

23. To keep the Z51 factory correct, the original screws were wire-wheeled and painted with Eastwood semi-gloss Extreme Chassis Black satin spray paint.

25 C4 Vette Outer Window Seal Dynamat

24. For additional help keeping the triple-black ’90 Z51 cool and quiet, Dynamat was adhered inside the door panels and doors. Measure the area to be covered and cut it out with a razor blade or mat knife.

26 C4 Vette Outer Window Seal Drill Rivet

25. Use the minimum sized drill bit needed to drill out the rivets. Do not drill any deeper than necessary or a hole might be drilled clean through the door.

27 C4 Vette Outer Window Seal Felt Window Guide

26. The window guides must move as far back as they can in order to move the window glass back towards the interior. Mark (scratch) the adjustment position of the two window guides before loosening (do not remove guides).

28 C4 Vette Outer Window Seal Installing Seal

27. With the three rivets drilled out, the old outer window seal can be removed. Sometimes they fall right off and other times you’ll have to fight to remove. If it is difficult to spread the clip jaws, open to release the outer seal from the door. These fought. Careful not to bend the new outer window seal, start at the rear of the door angling the clips into their corresponding holes and push with a slight twist the new outer window seal into place.

29 C4 Vette Outer Window Seal Insert Rivet First

28. Then it worked best to install the three rivets into the installed outer window seal.

30 C4 Vette Outer Window Seal Installed Rivet

29. The next step was to slip the pop rivet gun over the rivet and complete riveting.

31 C4 Vette Outer Window Seal Tape Barrier In Place

30. Do not glue in place. Duct tape is reversible and worked well to hold the door panel insulator in position.

32 C4 Vette Outer Window Seal Completed Door

31. Reverse disassembly to install door panels. The door panel was placed over inside the door and pressed from the top down into its place. The electrical connectors (plugs) were attached and the Phillips screws were reinstalled. Mothers’ products were used to clean and detail during and after assembly.


Eastwood Company

Pottstown, PA 19464


Hamilton, OH 45015

Corvette Central

Sawyer, MI 49125

Mothers Polish

Huntington Beach, CA 92649