Mustang Standard Seat Foam (1965-1966) Installation Instructions

Tools Required:
  • 1/2-inch Deep & Shallow Socket
  • 1/4-inch Drive Ratchet with Extension
  • Phillips Head Screw Driver
  • Pick
  • Needle Nose Pliers
  • Cutting Tool
  • Panel Removal Tool
  • Metal Shears
  • Hog Ring Pliers
  • Hog Rings (500 is plenty)
Install Difficulty:
  • Moderate
  • Moderate Project
1. My passenger’s seat foam has disintegrated to almost nothing. The springs are poking through and it’s become a safety hazard. It’s time to replace with new Mustang Standard Seat Foam.
Mustang Standard Seat Foam Install Image
2. While not nearly in as bad of shape, I may as well replace the driver’s side too.
Mustang Standard Seat Foam Install Image
3. The first step to replacing your seat foam is removing the seats from the car. Go under the car, locate four rubber body plugs and remove them to expose the Mustang seat track to body nuts. Depending on how old they are, you may need a flat head screw driver to pry them off. Once the nuts are exposed, remove them with the 1/2-inch deep socket and set aside. Do this for both sides. If you are missing some, or if they are just old now is the perfect time to replace them.
Mustang Standard Seat Foam Install Image
4. Now that the seats are loose, fold them over and lift them out of the car. Now is the perfect time the clean and vacuum the interior. Remove the four Mustang seat track plates from the bottom of the seat tracks and set them aside.
Mustang Standard Seat Foam Install Image
5. Now it’s time to begin disassembling the seat tracks. First remove the three Mustang seat track springs and set them aside. Then remove the set track adjuster, between both tracks. You will probably need to adjust the length to remove it. Simply turn the box until it is at a similar angle as the one pictured, and it should come out. Make note of which hole it came out of, and set it aside.
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
6. Now remove the Mustang seat tracks themselves. Unlock the tracks and lower them all the way. Use the Phillips head screw driver to remove the now exposed screw. Once it’s removed, push them up all the way and remove the screw on the bottom. You can now remove the seat tracks.
7. Now to remove the seat back from the bottom of the Mustang seats. Remove the Phillips screws from the two side panels and remove them.
8. Now use the needle nose pliers to remove the exposed cotter pins.
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
9. Once those are removed, use the pry bar on the larger arm and separate the seat back from the Mustang seat bottom.
Mustang Standard Seat Foam Install Image
10. Now remove the two washers that were behind the two arms. Remove the seat stop bolt with the 1/2-inch socket, and unscrew the adjuster stop plate. Now remove the seat back and discard it. If you don’t have a Mustang panel remover, the pry bar should work fine.
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
11. With the seat back removed, begin cutting all the hog rings along the edge of the seat.
Mustang Standard Seat Foam Install Image
12. Once this is done, you can rip the old Mustang upholstery off. Be careful not to twist the listing wire if you are planning on saving it. Cut it out of the upholstery if you are.
13. Now rip off the foam. Cut off any extra hog rings from the burlap if you can find them. Do this for both the bottom and top, for both seats. The burlap does not need to be saved, as the new foam has a protective backing, but you can leave it in if it’s in good shape. My driver’s side was okay, but the passenger’s side, not so much.
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
14. Now that you have the seats striped down, it’s time to start prepping the foam. You will need to cut holes in the foam for the Mustang hog rings to go through. Find the three groves on each side of the upholstery and cut through them. I found the easiest way to do this was to use the pocket knife and simply stab through the foam. Make the hole just big enough for your finger to fit through.
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
15. Now fit the foam over the Mustang seat frame. If you did it correctly and still have the burlap you should be able to see the burlap’s listing wire.
Mustang Standard Seat Foam Install Image
16. Now it’s time to cover the seats. Turn your upholstery inside out. Locate the listing channel and feed the listing wire through.
Mustang Standard Seat Foam Install Image
17. Now begin hog ringing the upholstery to the seat. If you kept the burlap, ring the two listing wires together, if not, ring it directly to the seat springs. Start by attaching the front three and work your way back from there.
18. Next attach the first hog ring on each side. Fold the front of the upholstery over the seat. The upholstery should be sticking up at the rear.
Mustang Standard Seat Foam Install Image
19. Now hog ring down the sides, alternating between them. Fold the upholstery over a little bit after each ring.
Mustang Standard Seat Foam Install Image
20. Now to stretch the upholstery and attach the back of it. This will get rid of the wrinkles.
21. Start with the top. Stretch it as far as you can, fold it over the frame, put in three to five hog rings. Be careful as the corners can rip easily.
Mustang Standard Seat Foam Install Image
22. Continue down each side, using four to five rings, stretching the fabric between each one. Pull the extra piping at the bottom tight and ring it to the frame. Use three to five rings on the bottom part of the Mustang upholstery as well. For the seat back, put one ring on the bar going across the back. On the seat bottom, the upholstery hog rings directly to the springs rather than the frame on the end. Be careful of the studs, as they can puncture the upholstery.
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
23. Now insert the Mustang door panel clips you removed earlier (if they’re in good shape) into the slots on a new seat back.
Mustang Standard Seat Foam Install Image
24. Line it up to the seat and mark where the clips are and use the pick to puncture holes at each location. Now replace the seat back and carefully press the clips into place.
Mustang Standard Seat Foam Install Image
25. Now find the location for the seat stop bolt. Make a hole, and thread it in.
Mustang Standard Seat Foam Install Image
26. Your seat backs are now finished.
27. On the bottom of the Mustang seats, locate the stud on each side. Make a small 'X' over the top, and press the upholstery over the stud. Do this for both seats, on both sides.
Mustang Standard Seat Foam Install Image
Mustang Standard Seat Foam Install Image
28. Now find the two holes for the seat stop plate. Puncture the upholstery, and replace the plate. Do this to both seats.
Mustang Standard Seat Foam Install Image
29. Now the seat bottom is finished. To reattach the seats, place the smaller of the two arms over the stud and line up the longer arm. Being careful not to rip the upholstery, use the pry bar to life the other arm over the stud. Replace the two cotter pins. The larger arm may need some tapping with hammer to get it to go down far enough for the cotter pin to go through.
30. Reattach the Mustang seat shield now. For the shield, loosely thread in the bottom screw and using the pick, punch holes in the upholstery where the screw holes line up. Then thread in and tighten all three screws.
31. Reattach the seat tracks opposite from the way they came off, bolt the seats back into the car and you've finished your Mustang Standard Seat Foam installation.