Loc: Eastern Washington
When my surge brakes were working there was almost no "clunking" when I hit the brakes. There certainly was when they were not working. Also, I barely had to press the brakes any harder than when not towing.
You can get the bearings re-packed and the brakes bled and adjusted for less than $100 at Les Schwaab or most other tire stores. Have you bled them yet? You might be able to see a leak on the inside of the rim if a wheel cylinder is leaking.
Loc: Cape Cod, MA
Disc surge are easy to test . . . just unplug the electrical to the trailer and try backing up. The trailer wheels should lock up. Make sure you are on a slight incline so that you are pushing the trailer uphill slightly when you back up.
Backing up does not usually work with drum brakes, because generally they are "free backing". The way I test drums is to activate the emergency lever on the coupler. Then, jack up each wheel slightly to see if it is locked up or spins freely. Then you got to release the emergency lever, when done.
Drum surge brakes are a pain in the arse period. The drum cylinders in these things despite having a rubber seal eventually suck in water, rust and seize up.
If you dont feel like the brakes are working, they probably arent. If you remove the emergency actuator cover, you use a crow bar to actuate the master cylinder.
Jack up one side of the trailer and spin the wheel. You can then actuate the brakes with the bar. You'll know immediately where you stand. If they stop but slowly, you may need new brakes or an adjustment.
Since you haven't said anything about checking the fluid level that should be done. If the master cylinder is full, then lean hard with your thigh on the brake actuator. It should move less than an inch or no more than half of the available travel. If that's OK problem is on the wheels.
Loc: West Palm Beach FL
I vote for the back up without some lockout protection. When my brakes were terribly worn (another post). I still could not back up without locking up the tires if I did not do something to lock out the coupler.
thanks Dale Gange - West Palm Beach Wow - its been 40 plus years since I was an Ensign -USNA 1970
The back-up thing only works with disc brakes. Drum surge brakes have cylinder plungers that only push the forward brake shoe, and rotational force lets the rear shoes do some work. When backing up, the reverse rotational force cause the rear shoes to move away from the drums, and there's not enough force being applied to the front shoes to do much good...
I put the ball on the trailer without hooking it up to the truck. We then use that as leverage. I usually turn the wrench on the bleeder end and wife works the hitch. I will say in and she pushes while I bleed the brake, then I will say out when I have it tight so it doesn't suck air back in and she will refill the reservoir when necessary.
There are kits you can get at an auto store to hook on the bleeder side so that 1 person can just pump and not have to keep opening and closing the valve.
2004 Supra Launch 22 SSV 5.7L 320 HP