bing tracking image

Dexter DX Series Electric Over Hydraulic Brake Actuator Review

content loading

Customers compare k71-651 to these similar products




Products Featured in this Video



Review of the Dexter DX Series Electric Over Hydraulic Brake Actuator


Speaker 1: Today we'll be having a look at the Dexter DX Series Electric Over Hydraulic Brake Actuator for Disc Brakes rated at 1600 PSI. This is part number K71-651. Here's what our actuator looks like installed. Now, the reason you're going to need an actuator like this is if you're running hydraulic disc brakes on your trailer and you don't have the ability to run a surge coupler. This is your only way to be able to power those hydraulic disc brakes, by supplying fluid pressure to them so they operate properly.Now, what sets this actuator apart from other electric over hydraulic actuators out there is that this one has a self priming pump. What that means is we don't need to worry about bleeding the actuator itself when we install it.

The actuator is self bleeding. The only thing we have to worry about bleeding is our brakes themselves. This makes the install and operation and general maintenance of this a lot easier. You can't use a hydraulic surge coupler on a fifth wheel, you have a have an electric over hydraulic setup like this.Also, this setup is better than a hydraulic surge coupler that you'll find on a boat trailer or other trailers like that that use those. The reason for this is, we don't have to worry about when we go to back up our trailer, the brakes being applied.

Our brakes will only be applied when our foot is on the brake pedal in our towed vehicle. Surge couplers apply the brakes on the trailer when the trailer moves forward, moving closer to the tow vehicle. This will apply the brakes whenever your brake controller inside your vehicle sends power to it, so it's an instantaneous response.Compared to others, this actuator does have a very large internal fluid reservoir. What that means is, we can hold more brake fluid. This gives us the ability to use this actuator not only on single axle trailers, but tandem axle trailers and triple axle trailers without a problem.

By having that much fluid, we'll have enough fluid to go through all the lines and run to all of our calipers, up to six in total.Now, this actuator is rated to put out 1600 PSI of line pressure, which is great, because a lot of hydraulic disc brake setups for trailers, they require at least 1500 PSI of pressure to operate properly. This one meets and exceeds those standards. Some other electric over hydraulic actuators, they require a separate breakaway battery. This kit, you can use a separate breakaway battery, or if your breakaway system to your trailer is hooked up to your house battery, such as they are in this fifth wheel, you don't need to worry about having a separate battery. As long as your battery produces at least nine amp hours, you can use the house batteries without a problem.Now, this kit is designed to work with your breakaway system on your trailer.

If your breakaway pin was pulled on your breakaway switch, and you can hear a pump operating, this means our brakes are being applied and this will bring our trailer to a stop. This is our brake actuator here. Coming off the back of it we have four wires. You'll notice they're about two feet long. Now, you may find that you need to extend your wires in some instances, such as the case that we're going to have today, because where we're going to mount our actuator isn't close to where our wiring junction is on our trailer.Now, we'll use some 10 to 12 gage heat shrink butt connectors, which we have on our website, and we'll crimp these onto the ends of our wires. Now, for video purposes here today, we'll be using the exact same color wire so you can easily see what's going on. We'll take our black wire here that we have laying around and we'll combine that with our black wire. Now we use a heat gun to shrink down our butt connectors.You'll want to be sure to use a heat gun over a lighter, because a lighter is an open flame and this is an indirect source of heat and it won't damage the connector. We have these available on our website if you need one. Here's what it looks like with all of our butt connectors shrunk down. You'll notice we have a nice proper seal all the way around, and this will provide a nice electrical connection where we don't have to worry about the elements causing corrosion or damage.Now we need to find a place to mount our actuator. In our particular case, we're working on a fifth wheel trailer, so we need to find a compartment that we can put it inside, and this basement compartment is a perfect location for it. I have it sitting on the floor of our basement compartment, and we can secure it to the floor using a couple self tapping screws. We'll just use our self tapping screws to secure it into place.Now we need to get our wires over to where our trailer's electrical wires are or your junction box, depending on how your wiring this up. I'm going to drill an access hole through this panel to get the wires to where our trailer wires are. Now we'll just enlarge this until it's big enough to pass all of our wires through. We went ahead and placed our wires through the hole that we drilled, where they come into another compartment in front of that one, which is where our trailer wiring resides. We'll go ahead and route these wires over to the wiring and start making our connections now.Our black, our white, and our blue wire ends up coming out over here next to the compartment, because this is where we need to tap in on the factory wiring. Now, our yellow wire, on the other hand, we have that stopped about the center of the trailer to the wire loom, and then it goes towards the front of the trailer underneath this panel. Now we need to attach this yellow wire to the cold side of our breakaway switch, and we use a 14 to 16 gage heat shrink butt connector, which we have available on our website.Now, our blue wire, this needs to attach to our trailer brake output. Now, we could have attached this at our junction box at the front of the trailer, but in order to save wire and to provide a cleaner install, since there's limited space to pass wires through underneath that panel, we're going to attach it to where our black wire is further back that it connects to the blue wire up front. It's the black wire inside this jacketed red wire right here. We'll go ahead and cut that wire in the middle, get those two wires twisted together. We'll place the other end of the black wire into the other end of the butt connector and we'll crimp it down.Now we need to attach our white wire to our ground, which goes to our tow vehicle. All of our grounds on our vehicle go to the negative terminal on our battery right here, so we can attach it here and still be okay. We'll measure off how much we need, we'll cut off the excess, strip back some insulation. Take a ring terminal, stick it over the wire, and we'll crimp it in place and we'll tighten it back down. Now, our black wire, we need to attach this to where our tow vehicle has this constant 12 volt wire, which does go directly to our positive post on the battery, so we can attach it here.Now that we have all of our electrical connections made, we need to go back to our compartment where our actuator's mounted. We've gone ahead and routed our brake line over to our actuator so we can make our connection now. We've also routed the brake line through the same passageway that we drilled a hole through for our wiring. With our plug removed, we'll take our fitting on our brake line and insert it into the fitting on our actuator, and we'll thread it into place. With our fitting now started, we'll tighten it down. Now we'll remove our reservoir cap from our actuator, and we'll fill our unit with brake fluid from a fresh container. Now that our actuator is full of brake fluid, we'll take our cap and we'll replace it.Now, our actuator is self bleeding, so once it's filled up with fluid we don't need to worry about bleeding the actuator itself, but we still do need to bleed our brakes. Now, there's two ways you can do this. One, you can plug your seven way into your tow vehicle and have someone manually operate the manual override on your brake controller to apply the brakes, but that's going to require a second set of hands. If you're doing this by yourself, you can still do it. You'll just pull the pin on your breakaway switch, and that's how we're going to do this today. I'll pull our pin, and now we can go back and open our bleeder screws to bleed our brakes.Okay, we're going to be working with our caliper that is the furthest away from our actuator. In this case, that is our passenger side rear caliper. We'll remove the cover over our bleeder screw, and when bleeding brakes you always want to make sure you're using the bleeder screw that's on top, above where your brake hose goes into. We'll be using a hose that goes into a bottle to contain our brake fluid so we don't make a mess. Now with our pin pulled, we'll crack open our bleeder screw. Okay, since this wheel, we had clean fluid coming through with no bubbles. We'll double check the level in our reservoir and we'll continue to bleed the remaining wheels on our trailer.Okay, now that we've repeated the process and bled all of our wheels, we need to double check our fluid level in our actuator. We'll just top it off accordingly. That completes our look at the Dexter DX Series Electric Over Hydraulic Brake Actuator for Disc Brakes rated at 1600 PSI, and this is part number K71-651.


Info for this part was:

Employee Jeff D
Installed by:
Jeff D
Employee Brent H
Installed by:
Brent H
Employee Joshua S
Video by:
Joshua S
Employee Dustin K
Video Edited:
Dustin K
Employee David F
Test Fit:
David F

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.