trailer brakes
 

Ok, looks like I'm having a problem with my trailer brakes. I did some work on the brake lines earlier this year and had to bleed the brakes. They didn't feel as strong after bleeding them, so I've always assumed that there was still a little air in them. Well, this past weekend I drove a couple of hours and when I stopped, I could smell the brakes. I touched one hub and nearly burned my finger! In the past the hubs were warm, but you could hold your finger on them. The drums were painted when the trailer was shot and I can see that a couple of them have a slight color change and one is definitely darker. You can clearly see where the shoes were rubbing on that drum. I know very little about brakes, so why arn't these retracting? I'm wondering if somebody might have tripped my break-away cable. My bearing buddies are fully extended on two wheels now, so does that mean that I need to repack the hubs? Did the seals burn out? There is a slight oily film on the hottest hub.

Cord,the most likely cause of burning brakes on a surge system is a small piece of crap lodged in the return port of the master cylinder. It allows pressure to be applied to the wheel cylinders but traps some pressure when the master cylinder releases(you accelerate). Remove the filler cap,pump out what ever fluid you can and look at the larger of the holes in the casting. Look close for a chunk of rust or the like. Carefully clean out the hole with a piece of wire and then gently apply the master(by pushing in on it) and observe the return hole as you release the master. If nothing comes out,it may still be plugged. Try reverse bleeding it by pumping brake fluid in through a bleeder screw. That will clear them most times. If the hub was that hot,yep,you need new seals and grease,maybe even the bearings.

trailer brakes
 

One common problem resulting from serious overheating of any sort is loss of wheel bearing grease. That will quickly kill the bearings. You probably will want to repack the bearings before using the trailer again and definitely find the cause of the heat buildup. You may want to take this opportunity to replace the bearings.

Good luck with finding the problem.

Cord, maybe you just have the pads adjusted wrong.....or too tight. There shoudl be a small rubber or metal plug on the back side of the backing plate. You can take a flathead screwdriver and move the "star" adjustment ring in or out to adjust the contact area or the pads. May be just that simple (hopefully)

I'm assuming these are drum brakes and not disk.. :)

Yea, they're drums. The heat is definetly from the brakes dragging. You can clearly see the heat was concentrated on the outside of the drum. Looks like I've got a nice big project for this weekend! :rolleyes:

btw-whats the easiest way to bleed the brakes? It has one of those in-line actuators. We used the truck last time to work it and I was wondering if there was a easier way? Anybody ever try one of those mitivacs?

Vacum bleeding is the best and easiest way. Just make sure you don't suck air around the bleeder screw. Remove the screw and apply a light coat of thick grease to the bleeder screw threads,it helps seal the screw to the wheelcylinder.

Checking the adjustment is easy,jack one wheel and spin it. should be relatively free to roll.

If the drums were that hot,prolly need new shoes too.

Yea, especially since I drove 120miles with them dragging. :(

Most common problem I've had with drum brakes sticking was rust in the wheel cylinders:(
The rust will form behind the outer boot and as the plunger comes out when the brakes are applied they stick since the rust makes the bore of the cylinder smaller.

Well, I pulled the drum off tonight. The outside of the drum was burned black. The entire inside of the brake is covered with soot. It's not the normal brake dust. It also had a burnt oder to the space. The seals look good and the grease looks normal. Not discolored at all and it smells just fine. The bearings look normal. The pads are glued on, not rivited. They have about 1/8" of material left. I can see that the pad has some pretty good cracks in it though.

I know from past experience that you can get a whole backing plate assembly for less than loose pads. The drums are brand new so they definetly can be turned down. I guess I'm just wondering how much I should really invest in this setup before looking at disk brakes. If the bearing look good and I put new seals in, should I buy new shoes? Should I bother to turn the drums??????

Cord, I was just looking into possibly upgrading my drums to disc. I was picking up some grease at Tom's Trailers ( you just gotta love the guy if you've ever had the displeasure of meeting him) and they quoted me $250 per axle for stainless steel discs. It might be worth looking into if you only have brakes on one axle. I've got them on all three. I don't know if you'ld have to change else, but I think it's just a simple swap and hook up the brake line. Good luck on your project! Steve

Did the conversion two years ago myself. Had single axle drums...converted to single axle disks. It didn't stop as well and the pads wore like hell. Last season I added disks to the second axle...that sucker STOPS now;) .
You must also remove a check valve from master cylinder. Instructions show you simply drive an awl through it. I did and it worked.
To do it right you should also add flex hose at the end of the metal lines going to the caliper as it moves unlike the stationary backer plate on drums.

509-I know exactly what you are talking about. If you want to shop for price take a glance at Norther tools. They are in Menomonee Falls, just north of Tom's. They often have the same item for significantly less than Tom's. Now if you need a oddball trailer part like a magnet for a 12" drum brake, Tom will have it on the shelf!

Trailer Parts
http://www.expediter.com/index.html

if you go with disc brakes you should get a reverse lockout solenoid it makes backing up easier, discs grab in both directions unlike drums

Go buy electric drum backing plates. They last longer than hydralics in fresh water, work better on the road, and will never form rust in the cylinders.

It costs the same as a hydraulic backing plate and you can re-use the drums. Just add some wires to the tongue and have the master cylinder welded in place.

You will need a controller for your truck but they are cheap - less than $100.

It works great in reverse down the ramp if you have a big boat!

Steve