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Replace the master cylinder on your Demco drum brake actuator. Fits all Demco drum brake actuators.
Features:
Specs:
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Today, we're going to take a look at the replacement master cylinder on the Demco brake actuators for drum brakes. Now, this replacement master cylinder assembly will fit the Demco trailer brake actuators for drum brakes. Trailer drum and disc brakes do require different PSI ratings, so that's why this part number can be used on drum brakes only. Drum brakes will usually need about a thousand psi pressure, whereas the disc brakes require 1600 PSI, so this master cylinder has the orifice size that'll produce 1,000 PSI pressure in your brake lines.The rubber boot end here on the master cylinder, this is what will connect to the actuator rod into brake actuator. The other end right here, it has the threads in it. This is where the orifice or the reverse solenoid will install for connection to the brake lines on your trailer.
What's nice about this master cylinder is a polymer construction, so there's no rust or corrosion. Does include everything shown here on the table. The master cylinder itself, the master cylinder cover, the gasket. Just install your gasket on the cover before you put it on there. Then you just line it up with the holes.
Does come with all the bolts and lock washers for them to install the cover down.And then the last piece it includes, the diaphragm style filler cap that you would just screw on there. Tighten it down, and then remove it to install your brake fluid. But that should do it for the review on the replacement master cylinder on the Demco brake actuator for drum brakes.
Customer Satisfaction Score:
98% were satisfied with this product
2% of customers were not satisfied
Ratings & Reviews
Master cylinder was perfect fit and works well.
All 3 parts that I ordered for my old trailer fit 100% perfectly. Paula was such a great help getting the right parts needed for my trailer.
When I ordered was not sure of fitting . But did fit perfect and getting trailer back on the road. Have been very happy with quality and very fast service.
Perfect condition
Prompt shipping
My new place for all my trailer needs
Will recommend to others
Fixed the problem
Exact product replacement with fast shi pping.
Was an exact fit, glad to be able to source replacement parts here.. my go-to place for trailer related parts
The price was the best I found and shipment was very timely. George even followed up on the day it was delivered to make sure all was fine.
I had just bought this trailer used and the etrailer site helped identify the proper replacement for a siezed master cylinder.
Have not yet installed this master cylinder. This is a very strong looking, plastic product. The original was cast iron. The plus to this? No rusting!
Also, this master cylinder also comes with a lid, if needed for your application, and the proper cap, whether the lid is used or not. And also, nuts, bolts, and washers, to complete the installation. These things are not pictured.
Blazing fast shipping!
Received the master cylinder in 4 days using standard shipping. The unit came with new bolts, lock washers, gasket, cover and cap. Bolted master cylinder in place and had the brakes (4) bled out in about a hour. I would recommend this master cylinder kit.
When I disassembled the surge brake assembly I found it was too corroded to be rebuilt and I needed to buy the full surge brake coupler. The staff at etrailer were great to work with and helped me return the parts I bought and got the full assembly to me quickly.
All I know is that dealing with etrailer was a wonderful experience. I don't usually leave reviews but I'm making an exception here.
1. I thought it was simple to determine what parts I needed through their website.
2. After said parts were ordered they arrived quickly and adequately packaged.
3. New parts fit perfectly and I promptly received an email making sure things were all good in the hood.
Very refreshing transaction. I needed a new master cylinder and little shock absorber for my surge brake trailer, and etrailer did not disappoint. Parts were correct and replaced some jank az stuff that was previously installed. All good now!
I just wanted to write back and tell y'all how great y'all are. I am enlisted in the Air Force here at Shaw AFB, so I don't have tons of money or lots of time. Your products came super-fast and was exactly what I needed. A little back ground on my situation, I have a 2004 boat trailer that has an A60 model Fulton folding Tongue that was discontinued in 2010. This made it impossible to find parts for it. I was able to use your website and the measurements listed to find replacements, the pictures also helped out a ton. By rebuilding my broken tongue i saved myself an easy $400-$600 to replace it. I received my order on Friday afternoon had the parts installed and was on my way to the lake in just over an hour. Perhaps my experience and success can help other people out with similar trailer tongues. i will definetly be using y'all for all my trailer needs.
Exactly what I was looking for to replace the dried up master cylinder for my boat trailer. Working great one year in.
Hello wide variety of parts easy access to buying them fit perfectly have no problem with it love it good product
Worked like it was supposed to.
Great service, but product took longer than expected.
It fit perfect It works great.
Master cylinder worked excellent. Sticker on lid said if your actuator case is threaded for fill cap don’t use the new lid that comes with the master cylinder. My threads were too rusted out to reuse so I used plasma cutter to enlarge opening to accommodate lid. This way no rusty threads and no rusty steel ceiling to contaminate fluid. 10 minutes well spent and looks better than new. This one won’t rust out either!
Order a part paid to have it delivered in 2 days ordered it on June 17th didn’t get it until 7/1?
The products were great. The shipping came USPS and was slower than expected. I would have preferred to have had UPS or fed-ex for the shipping. That may be my fault, but I don't remember and option for the shipping designating other than default.
This was an exact fit for my 2003 Karavan Boat Trailer absolutely great service part was on time and very simple install as this was an exact fit of the original master cylinder. I appreciate good service and parts that I don’t have to return.
Everyone was great to deal with and very fast shipping.
Works fine,direct replacement, not too tough to install,
Thomas
5/15/2026
Still working great
Four stars as this was a replacement unit for a leaking new unit right out of the box, manufacture defect...I assume that is the exception. The replacement part has worked great. Over the past year we have been using it and put a lot of miles on it. I have a trailer that we built is required to haul a heavy load and needs to go up and down many steep grades behind various vehicles of differing sizes and weights. The hydraulic surge brake system makes it worry free. Thanks for the warranty help from E-trailer...very good customer service. I will continue to shop with them as I have needs.
Marc
1/25/2026
I have not experienced any issues, works great. I would recommend this until to others.
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Crule
4/27/2018
Perfect