5-4.5" Bolt Circle 3,500 lbs. TruRyde® Trailer Axle Hydraulic Brake Kit - BK545HYD-IPS

The 5-4.5" Bolt Circle 3,500 lbs. TruRyde® Trailer Axle Hydraulic Brake Kit (Part #BK545HYD-IPS) provides strong, dependable hydraulic braking performance for 3,500 lb. trailer axles. This complete kit includes hydraulic brake assemblies and matching hub/drum assemblies, making it an excellent choice for boat trailers, utility trailers, and other applications requiring smooth hydraulic brake operation.

Key Features

• Part Number: BK545HYD-IPS
• Brand: TruRyde®
• Axle Capacity: 3,500 lbs.
• Bolt Circle: 5 on 4.5"
• Brake Size: 10" x 2.25" Hydraulic Drum Brakes
• Spindle: 84 Spindle
• Inner Bearing: L68149
• Outer Bearing: L44649
• Mounting: 4 Hole Brake Flange

Technical Specifications

• Pair of 10" TruRyde® hub/drum assemblies with 5 studs on 4.5" bolt circle
• Pair of 10" x 2.25" TruRyde® Dacromet coated hydraulic trailer brake assemblies with parts
• 4 Hole Mounting – works with Alko, Dexter, Quality, and other popular trailer axle manufacturers
• Fits 3,500 lbs. trailer axles with four-hole brake flange
• Includes full mounting hardware, bearings, seals, grease caps, spindle nuts, washers, cotter pins, tang washers, and lug nuts
• Fully assembled backing plates with shoes, springs, and cylinders attached and ready to be mounted (one left hand + one right hand)

This hydraulic brake kit offers reliable and responsive braking performance, especially well-suited for boat trailers and other wet or marine environments thanks to the Dacromet coating.

Questions about this TruRyde hydraulic brake kit or compatibility? Call our trailer experts at 1-800-866-3336.

Browse more Trailer Hydraulic Brake Kits.

QAI Certification Testing Standards for Trailer Brakes

QAI Laboratories is an independent, accredited third-party testing and certification organization. QAI certification provides assurance that trailer brakes have been rigorously tested to meet recognized safety and performance standards.

Primary Standards for Trailer Brakes

• CAN3-D313-M85 (R2012) — Canadian standard for Trailer Running Gear (axles, brakes, and suspension)
• CSA Z240 — Recreational Vehicles and Manufactured Housing standard
• FMVSS / CMVSS — Federal Motor Vehicle Safety Standards (U.S. and Canada) for braking performance
• UL Electrical Standards — Testing of brake magnets, wiring, and electrical components

What QAI Tests

• Braking performance and stopping power
• Electrical current draw and magnet strength
• Resistance to water, dust, heat, and corrosion
• Mechanical durability and long-term wear
• Self-adjusting mechanism performance (when applicable)
• Safety labeling and traceability

Trailer brakes that carry the QAI Certified mark (including many TruRyde® and Lippert® models) have been independently verified to meet these strict standards, giving you confidence in safety and reliability.

QAI Certified Trailer Brake Brands (Industry-Wide)

QAI Laboratories is a respected independent testing and certification organization. Below is the current status of major trailer brake brands regarding QAI certification:

Note: QAI certification is a strong indicator of independent safety and performance testing. Always verify current certification status on specific part numbers when safety is critical.