What Disc Brake Kit Is Recommended For 2021 Grand Design Momentum 397Th
Updated 09/02/2025 | Published 08/09/2025
Products Featured in This Question
Question:
I have a 2021 Grand Design Momentum 397Th. Which Disk Brake kit would you recommend?
asked by: Michael C
Expert Reply:
Hello Michael, thanks for reaching out. We should have the parts you need, and the DeeMaxx Disc Brake Kit # DE26AR may work for you, but there is no way for me to look up your camper online to know exactly what disc brake kit will fit. RV manufacturers just aren't that specific with their online literature.
Based on your GVWR I am assuming your have three 7,000 lb rated axles, but if you could check your axle sticker and confirm this that would be great. The 7K axles use a standard bolt pattern and bearing combination so as long as you can confirm that you can be sure the # DE26AR kit will work for you. It uses the # 25580 inner bearing and # 02475 outer bearing which are standard. The hubs are 8 on 6-1/2" bolt pattern with 9/16" studs. You will want to confirm the stud size for your wheels and make sure this matches. 7K axles should be 9/16" but please confirm.
This kit comes with everything needed to convert the triple axle trailer over to EOH disc brakes. The only other thing you would need is an EOH compatible brake controller in your truck. Most aftermarket controllers are compatible, like the Tekonsha P3 # 90195. Some factory controllers may not be compatible though.
Do you already have a brake controller? What kind?
(click to enlarge)
Product Page this Question was Asked From
DeeMaxx Disc Brake Kit w/ Actuator for Triple Axle Trailers - 9/16" Studs - 8 on 6-1/2 - 7K
- Trailer Brakes
- Disc Brakes
- Marine Grade
- 8 on 6-1/2 Inch
- Hub and Rotor
- 9/16 Inch Studs
- 7000 lbs Axle
- 16 Inch Wheel
- DeeMaxx
more information >
Continue Researching
- Search Results: window crank
- Search Results: trailer brake controller
- Search Results: rv window parts
- Search Results: rv window
- Search Results: accessories and parts
- Search Results: diode
- Shop: Hydrastar Electric Over Hydraulic Actuator Adapter Module for GM Brake Controllers
- Video: Review of DeeMaxx Trailer Brakes - Disc Brake Kit Triple Axle - DE26AR
- Shop: RV Designer Mini Blind Wand - 10" Long
- Shop: Interconnect Busbar for NOCO NLX Lithium Batteries - 8" Long
- Q&A: Will Deutsche Hydrapro CAM Adapter Module Work with DeeMax Actuator
- Shop: Fifth Wheel Hitch
- Shop: B&W Companion 5th Wheel Trailer Hitch w/ Slider - Dual Jaw - 20,000 lbs
- Shop: DeeMaxx Disc Brake Kit w/ Actuator for Triple Axle Trailers - 9/16" Studs - 8 on 6-1/2 - 7K
- Shop: Adapter Module for BrakeRite Electric Over Hydraulic Actuator - OE Ford, GM Brake Controllers
- Shop: Brake Controller
- Shop: Vehicle Tow Bar Wiring
- Shop: Trailer Wiring
- Q&A: Does 2022 Chevy Silverado Need Electric Over Hydraulic Actuator Adapter
- Shop: Roadmaster Universal Hy-Power Diode Wiring Kit
- Q&A: Is Hydrastar EOH Actuator Compatible With 2022 Chevy Silverado 5500 OEM Brake Controller
- Video: DeeMaxx Disc Brakes | Expert Insights from the Manufacturer
- Video: Checking Out the Dexter Tandem-Axle Trailer Equalizer Kit for 2-1/2" Slipper Springs
- Video: What to Know About the Adapter Module for BrakeRite Electric Over Hydraulic Actuator
- Search Results: deemaxx trailer brakes
- Video: Review of Andersen 5th Wheel Gooseneck Adapter - Aluminum Ultimate 5W Connection 2 Gooseneck - 3220
- Shop: Gooseneck Hitch
- Q&A: Is There Difference Between B and W Companion # BWRVK3400 and # BWRVK3400-5W
- Shop: Suspension Enhancement
- Q&A: Should I Go With The 5000 Pound Firestone Air Bags Or The 7500 Kit For My 2020 Chevy Silverado 2500
on Trailer Brakes
Jesse M.
9/2/2025
Hey Michael, did you have a chance to check your axle sticker and confirm the details for the disc brake kit? If you’re still looking for a solution, I’m happy to help.