Genuine Dexter 7" x 1-3/4" Hydraulic Uni-Servo brake assembly — a complete, factory-assembled brake unit for 2,000–2,200 lb trailer axles with surge (hydraulic) brake actuators. Available in Left Hand (K23-398-00) or Right Hand (K23-399-00). This single-plunger uni-servo design delivers responsive, smooth braking on boat trailers, snowmobile trailers, and light-duty utility trailers. Made in the USA by Dexter Axle — the industry standard in trailer braking systems.

🔧 Select Your Side

Choose Left Hand (LH / Driver Side) or Right Hand (RH / Passenger Side) from the dropdown above. Single-axle trailers need one of each; tandem-axle trailers need a pair of each. Always replace brakes in matching pairs for even wear.

⚙️ Key Features

• Genuine Dexter OEM – Made in USA: factory-quality replacement with exact-fit backing plate, shoes, wheel cylinder, hardware, and adjuster plug
• Uni-Servo Single-Plunger Design: smooth, progressive hydraulic braking — designed for use with surge brake actuators (NOT electric brake controllers)
• Brake Size: 7" drum diameter × 1-3/4" shoe width
• Capacity: 2,200 lbs per assembly / 2,500 lbs per pair
• 4-Bolt Mounting Pattern: 4" diagonal, 2-3/4" stud spacing — bolts included
• Fits 10" to 13" Wheels: standard fit for most light-duty trailer wheel sizes
• Manual Adjustment: adjuster plug covers access hole to keep dirt out — periodic adjustment required
• Pre-Assembled: backing plate, shoes, wheel cylinder, springs, and mounting hardware — ready to bolt on

📐 Specifications

• Manufacturer: Dexter Axle
• Dexter Part Numbers: K23-398-00 (Left Hand) / K23-399-00 (Right Hand)
• Dexter Assembly Numbers: 023-398-00 (LH) / 023-399-00 (RH)
• Brake Type: Hydraulic Uni-Servo (single plunger)
• Drum Size: 7" × 1-3/4"
• Axle Rating: 2,000–2,200 lbs
• Mounting: 4-bolt pattern (4" diagonal / 2-3/4" stud spacing)
• Wheel Fitment: 10" to 13" wheels
• Country of Origin: USA

🔄 Cross Reference & Compatible Parts

• Surge Brake Actuators: Dexter BP04-050 and similar hydraulic coupler / actuators
• Compatible Bearing & Seal Kits: L44649 inner / 10-9 outer / 10-60 grease seal
• Compatible Hub/Drum: Dexter 8-257-5UC3 (5 on 4.5) — pre-greased EZ-Lube version available

🔧 Common Applications

• Boat trailers (2,000–2,200 lb capacity)
• Small utility & snowmobile trailers with surge brake systems
• Small enclosed cargo trailers with hydraulic braking

⚠️ Important: This is a HYDRAULIC brake — requires a surge brake actuator or master cylinder. For ELECTRIC brake systems, use Dexter K23-026-00 (LH) / K23-027-00 (RH) instead.

💡 Pro Tip: After installation, bleed the hydraulic brake lines thoroughly and adjust brake shoes through the access plug on the backing plate. Re-adjust after first 200 miles of use.

Questions? Call or text AAA Trailer at 517-225-1991 — we stock Dexter, Lippert, Ultra-Fab, and TruRyde brakes, hubs, and running gear. Same-day shipping from Howell, Michigan.

📞 Call/Text: 517-225-1991   🌐 AAATrailer.com

What sets us apart is our dedicated team of knowledgeable professionals who are always ready to assist. Great customer service isn't just a promise—it's the foundation of our success. We invite you to visit our showroom or reach out for personalized advice. Whether you're purchasing online or stopping by, we're here to make your trailer journey seamless. Visit Us Today

• Address: 4675 East Grand River Ave, Howell, MI 48843
• Phone: (517) 225-1991 (Call or text)
• Hours: Monday to Friday: 10:00 AM - 5:30 PM | Saturday: By appointment

Thank you for considering AAA Trailer. We're excited to help you hit the road with confidence! If you have any questions, don't hesitate to contact us.

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 We will be happy to assist you with eligible returns, the return instructions, and the shipping address. If you need a return or exchange, send us an email so we can discuss a replacement.