Parts Needed to Add Brakes to 3,500 lb Trailer Axle
Updated 05/21/2026 | Published 05/18/2026
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Question:
I have a tandem axle boat trailer with 3500 axles. It has hydraulic surge brakes but only on one axle. I want to add brakes to the second axle. What componets do I need to order including brakes, drums, bolts, and fittings for the brake lines? The axle is standard 4x4 bolt pattern.
asked by: Brian C
Expert Reply:
Hey Brian, yeah we can definitely help add brakes to your 3,500 lb trailer axle but if you for sure have a 4 on 4 inch bolt pattern you'd have to also replace your wheels too. Normally you would just need brake assemblies and hub/drums.
For brake assemblies you would want the part # AKEBRK-35-SA and then for hub/drums you'd want the part # AKHD-545-35-EZ-K for a 5 on 4-1/2 inch bolt pattern.
Are you sure you have 3,500 lb axles? They don't ever normally have a 4 lug bolt pattern and instead need a 5 or 6 lug bolt pattern.
Product Page this Question was Asked From
Easy Grease Trailer Hub and Drum Assembly for 3.5K Axles - 10" - 5 on 4-1/2 - Pre-Greased
- Trailer Hubs and Drums
- Hub with Drum
- EZ Lube
- Pre-Greased
- L68149 / L44649
- Standard Grade
- For 3500 lbs Axles
- 1/2 Inch Stud
- 5 on 4-1/2 Inch
- 13 Inch Wheel
- 14 Inch Wheel
- 14-1/2 Inch Wheel
- 15 Inch Wheel
- etrailer
more information >
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on Trailer Hubs and Drums
Brian C.
5/18/2026
The 4x4 bolt pattern is where the backing plate bolts to the axle. The wheels are 5x4.5. What about the hydraulic line fittings. Is there a kit or do I need to buy the lines and such separate?