T BOOT

301A028-25-0 — T-Branch Boot Heat Shrink Boot for Motorsport Wiring

The 301A028-25-0 is a T-boot heat shrink boot from the Raychem/TE Connectivity 301A series, designed for T-shaped harness branch points, mid-loom breakout sealing, and harness junction environmental protection in motorsport and high-performance vehicle wiring harnesses. Heat shrink boots provide environmental sealing, strain relief, and a professional finished appearance at connector cable entry points and harness branch junctions — protecting both the electrical connection and the individual wire insulation from the moisture, vibration, and contamination of the motorsport environment.

T-Branch Boot — Sealing Harness Branch Points

Breakout boots provide environmental sealing and strain relief at harness branch junction points — locations where a single main trunk splits into two or more sub-looms. Without a boot at a breakout point, the individual wires in each branch are exposed to the motorsport environment at the split, creating a moisture ingress path into the harness interior and a strain concentration point where repeated harness movement will fatigue the wire insulation. A correctly fitted breakout boot seals the junction and distributes the mechanical load of harness movement across the boot body rather than concentrating it at the individual wires at the split point.

Why Heat Shrink Boots Are Essential in Motorsport Harnesses

Unsealed connector cable entry points and harness branch junctions are among the most common moisture ingress routes in a motorsport wiring harness. A correctly specified and installed heat shrink boot conforms to the connector body geometry and cable bundle shape, creating a sealed, reinforced entry or junction that prevents moisture from entering the connector cavity or harness interior, protects wire insulation from abrasion and flexing fatigue at the exit or branch point, and provides strain relief that distributes cable movement load away from the individual wires at the most mechanically vulnerable point in the harness structure.

Size Note — 301A028-25-0

This size variant is suited to a specific connector body and cable bundle diameter combination within the 301A series — refer to the datasheet for dimensional details. When specifying a boot, verify both the connector body outer diameter and the cable bundle outer diameter to confirm the boot will correctly fit the installation without being too loose (allowing moisture bypass) or too tight (preventing installation over the connector).

Installation

Heat shrink boots are installed over the connector rear before the connector is mated. The boot is slid back along the cable bundle, the connector is crimped, wired, and mated, and then the boot is positioned to cover the connector cable entry and shrunk in place with a heat gun. Correct shrink temperature must be used — consult the Raychem product specification sheet for the precise shrink temperature range for this boot to avoid over-shrinking or insufficient adhesive flow.

Available from Arctic Performance Parts

Arctic Performance Parts stocks Raychem/TE heat shrink boots across multiple families (462A, 382A, 342A, 322A, 301A, 222D, 202K) and a comprehensive range of size variants to support professional motorsport harness builders and workshops across Norway, Sweden, and Denmark. Lead time 1–2 weeks for quantities beyond current stock.