Brake Change For Your Bass Boat Trailer
(Standard axle hub assembly)
First I would like to say that this is the "Shade Tree Mechanic’s" version, as there are special tools that will make the job much easier. I will point out there the tools can be used in place of the elected tool I used.
Before you get started I would recommend that you contact the dealer that you purchased your boat from and see if they have replacement brake pads for your specific trailer. If you are as lucky as I am they will tell you with a little laugh that "You are going to have to go to a auto parts house and see if they can match them up". Unfortunately this presents a problem – the pads are still on the trailer. So you must first take them off and carry them to a parts house. My local parts house was very helpful in this matter; as a matter of fact I came to find out the brakes on my boat trailer are the same as the brake pads for a 84 model Ford Mustang.
Place your jack under your axle preferably at the point where your spring intersects the axle.
Raise the jack until it just contacts the trailer. Now loosen all the lug nuts on your wheel and tire assembly. Once that is done go back and lift your trailer with the jack until the tire is at least 1 inch off the ground. Now remove all the lug nuts from your wheel and tire assembly and then remove your tire. You should now be looking at your brake drum and hub assembly.
To save some busted knuckles, at this point take the time to bleed the any pressure that might be in your brake line by opening the bleeder port at the back of the brake assembly. This will allow you to pull your brake drum off easily when the time comes.
Next you will need to remove the cap to the hub giving you access to your axle nut and wheel bearings. Usually this cap will be pressed onto the hub. To remove it, tap the outside edge lightly with a hammer, as you are spin the drum and hub. After a couple taps it should start to separate from the hub it’s self, at this point you can use a flat head screwdriver to pry it the rest of the way off.
With the cap of the hub removed you should be looking at the axle nut with a locking device (similar to what you will find on your outboard prop hub) and a cotter pin.
Remove the cotter pin, then the locking device and finally the axle nut.
Be careful at this point as there is nothing holding your brake drum and hub onto the axle. Behind the axle nut you will have a large washer that separates the axle nut from the outer wheel bearing. Go ahead and pull that washer off.
Now slowly pull the brake drum and hub assembly off of the axle. The outer bearing will literally fall out of the hub as you do this so be prepared to catch it as you are removing the drum and axle assembly.
This is a good time to inspect your outer bearing and race for any damage. If you see any pitting or scratches on the bearing or on the race, it is time to replace them as well. Unless you have a new rear seal you will be unable to inspect the inner bearing. (Bearing inspection and replacement will be covered in a future article)
Also you need to look at your brake cylinder and inspect it for leaks, if you see any leaks you need to replace it. It’s very simple, just two bolts and a tubing nut.
Now that the brake drum and hub assembly are removed, it’s time to remove the springs and keepers allowing you to pull your brake pads off. This is where a brake tool will come in handy. It can be purchased at a local auto parts store. I use a pair of Vise Grips, which work just as well for me. Before you jump into removing anything take a good look at the brakes and housing assembly and make a mental note of how things are put together, if you need to take a Polaroid photo (hint: complete one side before starting the other that way you always have a finished product to look at if something gets confusing). The most important thing to remember is where the brake cylinder pin contacts the brake pad it’s self, when you are putting the new brakes back on you want to make sure this contact point is the same.
Looking at the brake housing assembly, at the top, there will be a stud that the left and right brake pad springs connect too. These springs are 3-4 inches long and stretch from the brake pads to the center stud. Using a pair of Vise Grips clamped onto the uncoiled portion of the springs, pull it towards the stud and lift it off. Be sure to pay attention to which one is on top as they both connect to the same stud it will be easier to remove the one laying on top first. After both brake pad springs are removed, you will notice there is an oval washer, remove it to keep track of it.
It’s time to remove the keeper springs. The keeper springs are the two regular coil springs just below center on the left and right side of the brake drum assembly. These are also easier to remove with the brake tool I mentioned earlier but I always like to do things the hard way. Not really the hard way but the way you have to do it if you don’t have the special tools. This coil spring has a cap at both ends of it with a small slit in the center of the caps. There is a free floating pin that comes from the back of the brake drum assembly through the back cap then through the coil spring and finally through the front cap, the end in this pin is flat and will fit through the slit in both caps. To remove the coil springs take a pair of pliers and push the outer cap towards the brake assembly housing, while twisting the cap to line the flatten portion of the pin with the slit then release slowly as to prevent the spring from flying off. This step is much easier said than done, but with some patience it’s not that bad. Going back on! Well that is a different story and is much easier with a third hand.
OK, now you can pull the brake pads from the brake housing assembly and lay them flat on the ground. You will notice that there is still one spring and a star adjustment cartridge holding the brakes together at the bottom. Simply remove the spring and cartridge, but make sure to pay close attention to which end goes to which side for reinstallation.
Before you start putting things back together with the new pads, you need to do some clean up work with the star adjustment cartridge. First take it apart. There are three pieces to it. The first is just an end cap that has probably slipped loose during the removal process. The second and third piece screw together, this is how your brakes self adjust. You need to unscrew these two pieces apart and clean the threads with a wire brush; sometimes you may need a pair of vise grips to get these two pieces unscrewed. When you are done they should screw together freely. Screw them together completely to create the shortest combined length and put the end cap back on.
Now match your new pads up with the old ones, you will find that one is larger than the other so you will want to make sure you reinstall them the same way. I like to lay my new pads next to my old ones and swap over the spring and star adjustment mechanism.
Install the star adjustment cartridge between the two pads and then install the connecting spring, make sure you have returned your cartridge to the shortest position possible.
Before you set your new pads up on the brake housing assembly, you need to do your self a favor. You need to retract the brake cylinder pin. The new brakes will be much wider than the old ones you just took off because they don’t have any wear to them yet. It’s not impossible but it will be very difficult to reinstall the brake drum if you do not retract the brake cylinder pin. To do this, simply push in on the brake cylinder pin while you open the brake bleeder port again.
(Could use a note to point out where to push)
Be sure to close the brake bleeder port before you stop pushing on the pin, this will prevent air from getting into your brake lines. Now you are ready to put everything back together. If you have a good memory the rest of this article is just the reverse of installation and should be easy to follow.
Set your brake pads with the spring and star adjustment cartridge installed up to the brake housing assembly. Make sure that the brake cylinder pin lines up with the cut away on the brake pad; this is the part that I suggested you try to take mental note of during removal.
(Could use a couple notes on this picture for the brake cylinder connection and the alignment pins)
Now slide the two alignment pins threw the brake pads and install the back coil spring caps (remember to twist it after pushing the pin threw to prevent the pin from falling out). Next put the coil springs on the alignment pins and finally the front cap. This front cap is going to be tight, because you will have to compress the coil spring with the cap to get the pin to slide through the slit, then once it comes through the slit you are going to have to twist the cap so that the flat portion of the pin is no longer inline with the slit and let the pressure off the spring. When both sides are done the brake pads will be held in place. Remember I said earlier that installing these springs would be much easier with a third hand. If you have someone to help you, have him or her hold the alignment pin from the backside of the brake assembly housing, keeping it still and straight.
Now install the oval washer over the spring stud and install your brake pad springs using the same Vise Grip method used during removal. It doesn’t matter which one goes on first.
(Could use picture notes on the first one)
Once complete look over the brake housing assembly and make sure everything is installed correctly and not loose. When all the springs are installed every portion of the brakes will be very snug. While you are checking that make sure to wipe the spindle free from any dirt or debris that may have collected on it during this process.
Once the spindle is clean it’s time to install the hub and drum back onto the spindle. Simply slide it over the spindle and over the new brake pads. If you compressed the brake cylinder enough this will be very easy. Next install the outer wheel bearing, then the washer and finally the axle nut. Now if you have a manual you might find a torque value for this nut, but if you had a manual you wouldn’t be reading this. SO, lets go with the "Shade Tree" version. With the axle nut finger tight start spinning the hub and drum assembly and tighten the axle nut as the same time. When then hub starts to bind because the axle nut is to tight stop everything and back the nut off ¼ turn. Now spin the hub again, is it spinning freely? If not back the nut off another ¼ turn. If so check for in and out play. Grab a hold of the brake drum and pull it towards you and push it away from you, you should feel no movement. Now if the hub and drum assembly spins freely with no drag and there is no in and out movement you have a good manual torque, or what a "Shade Tree Mechanic" would call a calibrated elbow! Next you want to install the locking device and a new cotter pin. And finally install the hub cover by gently tapping it back into place.
Everything is together, all that is left is to lube the bearing and check the brake fluid. Your bearing grease level should be pretty good still but it is always a good idea to give them a couple extra shots of grease to make sure. To check the brake fluid level, find the reservoir cap that is usually in the tongue of the trailer and ensure it is full to the level suggested on the cap (usually with in ½ inch of the top).
Mike Cork
