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Rear Stainless Braided Lines That Firm Up the Pedal and Complete the HD Challenge Rear Brake Upgrade on the TRX
The Rotora L.67421 is a direct-fit rear stainless steel braided brake line kit for the 2021-2023 Ram 1500 TRX, replacing the factory rear rubber brake hoses with PTFE-lined stainless braided lines that exceed DOT and FMVSS 106 standards. While the Rotora HDTRX-380x32 HD Challenge rear kit includes stainless lines in the box, the L.67421 is the correct standalone upgrade for TRX owners who want to replace their rear factory rubber hoses independently of a full system change, or who are retaining the stock rear calipers and only upgrading lines. By eliminating rubber hose expansion under braking pressure, the L.67421 improves rear brake pressure transmission and pedal consistency, reducing the sponginess that develops in factory rubber hoses under heat and hard use. Every line is 100% pressure tested to 3,500 PSI before leaving the factory.
Note: No returns are accepted on brake lines for any reason. If threads are stripped prior to installation, chase them with the appropriate die before proceeding.
Key Features
- Rotora L.67421 direct-fit rear stainless braided brake line kit for 2021-2023 Ram 1500 TRX
- PTFE inner core with stainless steel braid eliminates hose expansion under hard braking pressure
- Blue abrasion-resistant PVC outer jacket with strain relief at all fittings
- Exceeds DOT and FMVSS 106 standards for brake hose performance and safety
- 100% pressure tested to 3,500 PSI per line before shipment
- Firmer, more consistent rear pedal feel compared to factory rubber hoses
- Companion upgrade for the Rotora HDTRX-365x36 front HD Challenge system when rear lines are upgraded independently
- Complete kit includes all fittings, hardware, and installation instructions
- Made in USA
Fitment
| Year Range | Make | Model | Trim |
|---|---|---|---|
| 2021-2023 | Ram | 1500 | TRX |
Specifications
| Detail | Value |
|---|---|
| Part Number (MPN) | L.67421 |
| Brand | Rotora |
| Type | Rear Stainless Steel Braided Brake Lines |
| Fitment | 2021-2023 Ram 1500 TRX |
| Inner Core | PTFE (Teflon) |
| Braid | Stainless steel |
| Outer Jacket | Blue abrasion-resistant PVC |
| Pressure Rating | 3,500 PSI (100% tested) |
| Compliance | Exceeds DOT and FMVSS 106 |
| Country of Origin | USA |
| Returns | No returns accepted on brake lines |
| Prop 65 | Yes |
| UPC | N/A |
What's Included
- Complete rear stainless steel braided brake line kit for both rear corners
- All fittings, Banjo bolts (where applicable), crush washers, and retaining hardware
- Installation instructions
About Rotora
Rotora designs and manufactures performance and heavy-duty brake systems and supporting components for street, track, and extreme-duty applications. All Rotora brake line products are manufactured to exceed DOT and FMVSS 106 standards, 100% pressure tested, and engineered to complement Rotora's HD Challenge and Street Challenge brake system upgrades on specific vehicle applications.
Related Parts on Our Site
- Rotora HDTRX-380x32 HD Challenge Rear Brake System 2021-2023 Ram 1500 TRX
- Rotora HDTRX-365x36 HD Challenge Front Brake System 2021-2023 Ram 1500 TRX
- Rotora L.67149 Front Stainless Steel Braided Brake Lines 2021-2023 Ram 1500 TRX
Frequently Asked Questions
What is the Rotora L.67421?
The Rotora L.67421 is a direct-fit rear stainless steel braided brake line kit for the 2021-2023 Ram 1500 TRX. It replaces both factory rear rubber brake hoses with PTFE-lined stainless braided lines that exceed DOT and FMVSS 106 standards, are 100% pressure tested to 3,500 PSI, and eliminate rear hose expansion under hard braking to deliver firmer, more consistent pedal feel at the rear axle.
Is the L.67421 included with the HDTRX-380x32 rear HD Challenge kit?
The Rotora HDTRX-380x32 rear HD Challenge system includes a pair of DOT-compliant stainless steel braided brake lines in the kit box. The L.67421 is the standalone rear line kit for TRX owners who want to upgrade factory rear hoses without purchasing a full brake system, or who are pairing the upgrade with the front HD Challenge kit (HDTRX-365x36), which does not include lines.
Does the L.67421 fit the 2022 and 2023 Ram 1500 TRX?
Yes. The Rotora L.67421 is a direct fit for all 2021, 2022, and 2023 Ram 1500 TRX models, engineered specifically for the TRX rear brake hose routing and fitting specifications.
What standard does the L.67421 meet?
The Rotora L.67421 is manufactured to exceed both DOT and FMVSS 106 requirements for hydraulic brake hose performance, pressure resistance, and fitting integrity. Every line is individually pressure tested to 3,500 PSI before shipment.
Should I replace front and rear lines at the same time?
Yes. For a complete line upgrade on the 2021-2023 Ram 1500 TRX, replacing both front and rear simultaneously is recommended. The Rotora L.67149 front stainless braided brake line kit is the companion product for the front axle and is sold separately.
Will the L.67421 work with the factory rear calipers?
Yes. The L.67421 is a direct-replacement hose upgrade and is fully compatible with both the factory stock rear calipers and aftermarket rear caliper upgrades including the Rotora HDTRX-380x32. No caliper or bracket modification is required for the hose installation.
Can I install the L.67421 myself?
Installation requires basic mechanical experience, a flare nut wrench set, and the ability to properly bleed the brake system afterward. Proper bleeding is critical. If stripped threads are encountered at the factory hose fittings, chase them with the appropriate die before installation. Rotora does not accept returns on brake lines under any circumstances once they have shipped.
What is the return policy on the L.67421?
No returns are accepted on brake lines for any reason. All sales are final once the order is placed. Verify fitment and compatibility before purchasing. Contact us with any fitment questions before ordering.
Installation Instructions
- Safely lift and support the rear of the Ram 1500 TRX on jack stands or a vehicle lift.
- Remove the rear wheels to access the brake hose connections at each rear corner.
- Place a catch container under each brake hose connection to capture residual brake fluid.
- Using a flare nut wrench, loosen and disconnect the hard brake line from the factory rubber hose at the chassis bracket fitting. Cap the hard line immediately to limit fluid loss.
- Remove the factory rubber brake hose retaining clip from the chassis bracket and disconnect the lower end of the hose from the caliper Banjo fitting. Discard the factory copper crush washers.
- If threads at any fitting are stripped, chase them with the appropriate die before proceeding.
- Install the Rotora L.67421 stainless line with new copper crush washers on both sides of the caliper Banjo fitting. Thread the Banjo bolt in by hand first, then torque to 14 ft-lbs (19 Nm).
- Route the stainless line up to the chassis bracket along the original hose path. Connect to the hard line fitting and install the retaining clip.
- Tighten the hard line fitting using a flare nut wrench to 14 ft-lbs (19 Nm). Do not overtighten.
- Repeat on the opposite rear corner.
- Bleed the rear brake circuit thoroughly. Confirm no leaks at all fittings before moving on.
- Reinstall wheels, torque to factory spec, and test pedal feel before driving.
WARNING: This product can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.
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