trailer problems

Hello all. I recently purchased my first boat, an '88 Ski Nautique 2001. It has the original single axle trailer w/hydraulic drum brakes. Are there any resources for information (schematics/diagrams) or parts references for the trailer? The brakes are not functioning at all. Here is a rundown:

1. The brake lights don't work (all other lights function fine).
2. The tongue flops up and down when braking/accelerating (I'm guessing there is no hydraulic pressure to act against).
3. If the cap on top of the tongue is the reservior for brake fluid the master cylinder will need to be replaced (looks more like bearing grease in there).
4. There also appears to be some type of small shock absorber next to the master cylinder which I'm sure it shot as well and will need to be replaced.

This is my first time dealing with trailer brakes so any advice from veterans will be greatly appreciated. Oh yeah, any online resources for the parts?

TIA

-Ryan

If lights go out when the brakes are on, the common is incorrectly wired or the trailer is floating and not tied to chassi ground.

Likely,when this occurs, both filaments will be glowing when the running lights are on,

Ryan:

It appears that you described an Attwood hydraulic brake coupler. Rebuild parts are availble and I just reassembled mine last night. The PO welded my couple to the trailer tongue, so I had to go the rebuild route. Rebuilding is cheaper than replacement for the couplers and not very hard to do.

1. Remove the through bolt at the tongue pivot (bottom bolt).
2. Remove the cover at the back of the coupler, if present. May be pop riveted in place.
3. Remove the nut and washer at the shock absorber rod. push the rod out of the mounting hole.
4. Disconnect the brake line from the master cylinder. Remove the four bolts holding the master cylinder to the coupler. remove the master cylinder.
5. Remove the shock absorber and spring assembly (break away device).
6. Remove the plastic fluid fill cap.

I suggest you buy the following parts: master cylinder, fluid fill cap, Piston boot. Inspect the shock absorber. If the piston/rod moves easily or catches, replace the shock absorber. They tend to last a long time and may not need replacement...mine did not.

All the new parts come with an exploded view showing reassembly.

I sugest you unbolt the brake assembly and through it away. Buy the entire assembly new (backing plate, shoes, cylinder, etc.) and bolt it on. I suggest the free backing type.

Using alcohol, flush the brake lines before reconnecting. then fill and bleed and you are done. To bleed, mount the ball hitch in the coupler and use it as a lever to pump up the master cylinder while a buddy opens and closes the bleed screws.

One last thing: I suggest silicon brake fluid so as to eliminate the fluids tendency to absorb water. You can use silicon fluid since all hydraulic parts will be replace and there is no chance of mixing conventional fluid with the silicon fluid.

Your welcome. I probably would have replaced the entire coupler as well, but like I mentioned mine was welded to the trailer tongue.

Forgot to mention the other benefit to silicon brake fluid...it does not attack paint like conventional fluid.

Well, starting at the actuator end of things, I simply poured in a bit of alcohol using a tukey baster. I then used my compressor to blow the alcohol through. I repeated this process until clear alcohol came out the other end of the lines. FWIW, my compressor has a drier fitted, so I was not concerned about introducing moisture that could condense inside the lines...but if you do not have a drier fitted, the alcohol should evaporate off any moisture anyway.

Remember to inspect the rubber brake line where the rigid line transfers to the axle(s).