Today were looking at the Demco 10 inch marine brake assembly, part number 40715. This is the right hand side and the way we tell this is by looking at the brake shoe linings. The forward shoe will be smaller than the rear shoe or primary shoe. This is our single servo setup which means the wheel cylinder will have piston that will push out against the brake shoe creating a wedge effect inside the brake drum. This assembly mounts on a 4 bolt flange which is already pre drilled in the backing plate to sit on top of your 4 bolt flange studs. As initial setup, we use a star wheel adjuster to adjust the brake shoe linings out to create a light drag on the brake drum, then as the brake shoe linings wear, we can remove the grommet in the backing plate to adjust the star wheel out to keep that nice even braking.
When we couple the right hand side with the left hand side, we can create up to 3500 pounds in braking capacity. To measure our brake shoe assembly, we go from the width of the brake shoe lining to the other brake shoe lining and see we have 10 inches and then we can measure the thickness of the brake shoe which is 2-1/4 inches. This assembly will fit a 10 inch by 2 inch hub drum assembly. This assembly is also set on a galvanized backing plate making it good for marine applications. It also a fall away brake system which means there will be minimal drag when backing up making it a good application for trailers with braking couplers.
There you have it for the Demco 10 inch marine brake assembly part 40715.
This Old Trailer: Changing Hydraulic Trailer Brake to Electric
Today on This Old Trailer we are going to replace hydraulic brakes with electric brakes. Basically it is going to be a matter of taking off the tires, removing the hubs, go ahead and removing the backing plates and drain the hydraulic lines of fluid, and then going ahead and bolting on the new brakes. We will start off, obviously, by taking the wheels off. OK, go ahead and remove the dust cover here. It is an E-Z Lube spindle so this has a tang washer that we need to bush back down so we can unlock the castle nut right here. Just push it back down. Now we should be able to take the hub right off. The next task is to go ahead and disconnect the hydraulic lines. We have that disconnected. Now we need to pull the clip out so we can release this part here. And that is just a little piece of metal right here that you can just pry out. Alright, now we can unbolt this at the back of the hydraulic backing plate. Alright, now we can unbolt the backing plate from the flange on the axle. Now we are down to our bare axle. We will clean it up a little bit and then reinstall the brakes. 1:24
This Old Trailer: Electric Trailer Brake Installation Part 1
Alright, today on This Old Trailer, what we are going to do is install electric brakes. Right now this trailer does not have any brakes on it whatsoever, so it has two drag axles. So the first thing that we need to do is go ahead and take off the rear wheels. And then we will go ahead and take off the hubs. At this point we will take off the dust cap on our axle. And basically what you want to do is on this particular unit we have an E-Z Lube cap, so it fits kind of tight. It is a good idea to go ahead and rotate the hub and lightly strike it and then I will just back it off with a screw driver behind the flange. And then pry it off. Alright, let us wipe off the excess grease on the end of the spindle here and we will get to our tang washer. And we will release it so we can back off the castle nut. Alright, we have it cleaned up a little bit. Now right here, this is the tab I was talking about. That is our tang washer. Take this. Push it down flat to the flat spot on our spindle and then you can take the castle nut off. 1:07
All right today we are going to show you a typical brake inspection. Basically what we are going to do is take off the brake hub here and we are going to inspect the brakes, the linings, the springs, and the display cylinder inside. First off we will go ahead and take off the dust cap. In this case it is a bearing buddy. Next, is taking out the locking pin. There is either a cotter pin that goes in the center here but once you get that lock washer off you have to go ahead and just take off the nut and pull your whole hub off. First thing you want to check for is grease on the linings, and sure enough we have got grease all over these linings here. Also on this side here and probably smeared around over to the other side as you can tell.
All right today we are going to show you how to bleed hydraulic brakes on a trailer. First off you want to top off your master cylinder, with appropriate fluid. To pump the fluid from the master cylinder out, there is a couple of different ways of doing it. Sometimes it will have the emergency lever the and the safety chain will pull. Okay what you can do is unbolt the plate that holds the lever in place and then use that lever to actuate the master cylinder and force the fluid through. Some of them, you are going to have to go where the ball goes and manually activate it. Pull it in and out. Or like on this model here there might be a little lever underneath here that you could use.
Trailer Hub Brake Magnet Replacement Demonstration
When one wheel does not seem to be stopping as quick as the others it may be because the brake magnet needs to be replaced. We put together a short video to help you recognize this problem and to show you how easy it is to fix it. Keep your trailer safe for yourself and others on the road by checking and replacing parts like the brake magnet when needed.
Trailer Brakes and Wiring Installation
Today we are going to show you how to install brakes on a trailer that does not have existing brakes. It is actually pretty easy to do. It is just very time consuming. There are a couple of things you want to look out for before you start. You want to step behind your trailer, and look behind the existing hub you have. Make sure you have a flange like this on the axle. It is this 4-bolt flange on here; if you have that on your axle you are pretty much home free. This size flange has four bolts. You will see it on 3,500- pound axles like we have here. You also see it on 2,000- pound axles. On a 3,500 -pound one you would probably use a 10- inch drum and on a lighter axle, 2,000 pounds, you probably would use a 7- inch size. Also you notice we have the hub missing. We have to take that off because the hub and drum assembly is all in one piece. It is not like the automotive application. You have to take off the old hub, discard it, and start off fresh.
