Fix a jamming Cybex Pallas S-Fix

My Cybex Pallas S-Fix car seat already as new had a tendency to jam. Specifically its mechanism to retract the isofix mounts. The problem got progressively worse. Here's how I fixed it.

The first step was to detach the seat from the base. Surprisingly it's only four little plastic pieces that keep them together. Two screws torx screws are in the back of the base (one already undone in the picture): cybex Two further on the bottom: cybex Additionally I had to detach two springs on either side: cybex which were hooked onto these plastic pieces: cybex With the base free the next thing to do was to unscrew a plastic cover. Six screws on top: cybex and one on the bottom of the base: cybex

Then the mechanism was unveiled. Pulling the light-grey lever moves two plastic sled, encircled in red. cybex As seen below sled had not enough clearance along the way. Sometimes it took considerable force to get it past the conflict points, sometimes it hopelessly jammed. cybex

I melted the material away with a soldering iron. cybex I had to remove quite some material to ensure smooth travel: cybex

After the fix the mechanism can be operated with one finger. Problem solved!

When putting the seat back together I noticed that the plastic pieces that hold the seat and base fit in one way only: cybex