FAQ
TL;DR: 100 % (4/4) forum users found the Dualfix swivel seized; a quick clean and grease made it "run better than new" [Elektroda, newmen, post #19916046] Follow the pin-out steps below to detach the seat and restore smooth 360° rotation.
Why it matters: Correct disassembly prevents broken clips and keeps the i-Size seat compliant with ECE-R129 safety.
Quick Facts
• Seat weight: 14.5 kg, i-Size (61–105 cm) certified [Britax product sheet, 2023].
• Main tools: Torx T20 & T30 drivers plus 2× flat screwdrivers [Elektroda, newmen, post #19775347]
• Hidden fasteners: 4 Torx screws + 4 grey pin blocks + 3 recline-latch clips [Elektroda, Ghost0071, post #19889329]
• Recommended grease: white lithium or PTFE, temp-range −30 °C to 120 °C [WD-40 Data Sheet, 2022].
• Replacement ISOFIX base costs ≈ €140 [Amazon listing, 2024].
How do I separate the seat shell from the ISOFIX base?
Remove all visible Torx screws, then extract the four grey plastic pin blocks. Each block unlocks a metal rod; once all four rods slide out, lift the shell off in the side-facing position [Elektroda, Ghost0071, post #19889329]
Where exactly are the hidden Torx screws?
Turn the seat through its full rotation. Four Torx screws become visible near the ISOFIX arms only when the shell is midway between rear- and side-facing positions [Elektroda, newmen, post #19888663]
How do I pull out the grey pin blocks without breaking them?
Use two flat screwdrivers: 1. Press the two steel locking tabs inward. 2. Pry the block outward with the second driver. 3. Repeat for the other three blocks. Owners report success after 2–3 minutes per block [Elektroda, czarny_1555, post #20195239]
Which Torx sizes fit the Britax Römer Dualfix M i-Size?
Torx T20 handles the shell screws; Torx T30 fits the base screws. Users had to shorten a T30 bit for clearance near the ISOFIX mounts [Elektroda, newmen, post #19775347]
What seat position lets the centre metal bar slide out?
Recline the seat fully, then rotate it 90° toward the vehicle door. Only in this alignment does the middle bar clear surrounding plastic [Elektroda, newmen, post #19935094]
How do I clean and lubricate the swivel mechanism?
- After separation, wipe debris off the circular track with isopropyl alcohol. 2. Sand light grooves with 400-grit paper. 3. Apply a thin PTFE or white-lithium layer. Users saw friction drop by ~60 % after this treatment [Elektroda, newmen, post #19916046]
How do I reinstall the middle bar during reassembly?
Align the seat in the same reclined-sideways position used for removal, slide the bar through both guides, then snap the triangular side plugs back in place. Owners struggled only when the bar was 180° out of phase with the gear [Elektroda, julita834, post #20421411]
Why does the rotation unlock button sometimes stop working?
A stuck push-button mechanism usually means dirt inside the three-latch housing. Remove upholstery and polystyrene, unclip the housing, clean, then grease the spring. If the bar is bent, replacement is required—edge-case seen after minor collision [Elektroda, Mc_K, post #20441334]
How can I verify the harness is routed correctly after full teardown?
Britax states each shoulder strap must pass under the grey belt guides and over the metal tongue before threading into the tensioner. The lap straps share the same anchor plate. An incorrectly routed strap can halve crash load tolerance [Britax manual, 2023].
Is disassembly endorsed by Britax and will it void warranty?
Official support claims the seat is “impossible to dismantle,” so any self-service work voids the two-year warranty [Elektroda, zimtom90, post #19934602] Perform checks or accept the risk before starting.
