Difference Between Single, Dual and Free Backing Servo Brake Assemblies
Question:
Just a few questions. Looking to replace my trailer brakes on my boat trailer. They are hydraulic drum brakes. I believe 12inch by 2 inch wide. I see there are a few terms I am not exactly sure what there talking about. Dual servo? s single servo.. Free backing?? Any help would be great. Its a triple axle trailer with drum brakes on 2 of the 3 axles. I travel alot with it and the boat and trailer together weigh almost 11k lbs. Any suggestions on what to use??
asked by: Jim P
Helpful Expert Reply:
The biggest difference between the servo styles that you'll notice is between free backing plates and the others. The free-backing plates will allow your trailer to back up without having the brakes lock up. With surge brakes typically when you go to reverse the trailer it pressurizes the brake system which locks the wheels up. Free backing setups are designed to allow the pressure to build but not activate the shoes of the assembly so the trailer can back up.
Some surge brake trailers have reverse lock out systems built into them so the free backing plates aren't needed. The difference between single and dual servo is that for dual servo the wheel cylinder pushes on both shoes instead of just one. Typically this is seen on the higher capacity brake assemblies.
I attached a link to a page that has all of the hydraulic drum assemblies we offer.
Product Page this Question was Asked From
Hydraulic Brake Kit - Uni-Servo - Free Backing - Dacromet - 10" - Left/Right Hand - 3,500 lbs
- Trailer Brakes
- Hydraulic Drum Brakes
- Marine Grade
- Free Backing
- Manual Adjust
- Single Servo
- 10 x 2-1/4 Inch Drum
- 3500 lbs Axle
- 14 Inch Wheel
- 14-1/2 Inch Wheel
- 15 Inch Wheel
- etrailer
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Q&A: What is Difference Between Uni Servo and Duo Hydraulic Brake Assemblies for Trailer
- Shop: etrailer Universal Tow Bar Cover - 40" Long x 14" Wide
- Shop: Demco Hydraulic Trailer Brakes - Free Backing - Galvanized - Left/Right - 10" - 3.5K
- Shop: Dexter Hydraulic Trailer Brakes - Free Backing - 12" - Left/Right - 7K
- Shop: Weigh Safe 180 Hitch 2-Ball Mount - 2" Hitch - 6" Drop/7" Rise - 12.5K - Chrome Balls
- Shop: Hydraulic Trailer Brake Kit - Uni-Servo - Free Backing - 10" - Left/Right Hand - 3,500 lbs
- Shop: Demco Air Force One Flat Tow Brake System for RVs w/ Air Brakes - Wireless Monitoring - Proportional
- Shop: Dexter Hydraulic Trailer Brakes - Parking Brake Ready - Uni-Servo - 12" - Left/Right - 7K
- Search Results: brake line
- Q&A: Comparing Free Backing and Duo Servo Hydraulic Brake Assemblies
- Q&A: Does The Replacement Brake Shoes For Titan Hydraulic Trailer Brakes Fit The Left And Right Hand Side
- Q&A: Replacement Brake Magnet Needed for a Hayes M144 or AL-KO K568111 Brake Magnet
- Search Results: 9599019
- Video: All You Need to Know About the Blue Ox Avail Non-Binding Tow Bar
- Video: Breaking Down the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit
- Video: 2021 Jeep Wrangler Unlimited Blue Ox Avail Non-Binding Tow Bar: Complete Installation
- Video: In-Depth Review of the Demco Air Force One Flat Tow Brake System for RVs w/ Air Brakes
- Video: Hands-On with the Blue Ox Avail Non-Binding Tow Bar
- Search Results: dexter 8~219
- Search Results: dexter trailer brakes
- Search Results: 12 dexter brake shoes
- Search Results: tekonsha 90160
- Video: Let’s Check Out the Replacement Rail Cover for Demco 18,000-lb Auto-Slide Fifth-Wheel Hitch
- Video: Detailed Breakdown of the Ventline Ventadome Trailer Roof Vent
- Search Results: b
- Q&A: Recommended Replacement for Atwood Surge Brake Actuator 85778
- Q&A: Will Hitch Installation Interfere With Hands-Free Liftgate On 2024 Acura MDX
- Q&A: How Do I Know If I Have Free-Backing Brakes?
- Article: Trailer Drum Brakes vs. Disc Brakes: Making the Decision
- Article: How Much Does a Boat and Trailer Weigh?
on Trailer Brakes
