If you are re-using your drum brake master cylinder you have to pull the residual valve out of the master cylinder.

Depends on who manufactured your surge actuator how to go about doing it. But usually it's just a matter of draining the master cylinder, pulling out the piston and removing the residual valve. Reassemble. Pretty simple.

For example:

http://www.championtrailers.com/remo...dual_valve.htm

You also need a reverse lock out solenoid for disc brakes if you didn't already have one. Drums will slip in reverse, discs will not.

Don't forget to remove the inline restricter orifice . It should be a small brass fitting located close to your master cylinder .

I have a free backing set up now. Etrailer seems to think I need a whole new acuator and shouldnt modify it, but I think they are wrong. But Ill have to take the master apart and look at it.

Does the reverse solenoid go behind the acuator and do I need a new plug to go into the truck for lights and what not.

thanks that answers a lot of my questions on the picture, seems straight forward.

got a picture

The lockout solenoid goes between the master cylinder and the brakes. Should screw right into the back of the master cylinder. You'll need a 5-pin wiring harness. The blue from the harness will go to the solenoid. Sometimes you can find a 5 pin that the 4 pin will piggyback onto, then all you have to do is wire the new wire to the solenoid. Or just rewire the trailer to a 7-pin so you don't have to worry about an adapter. The reverse solenoid is actuated off of the reverse light pin.

As the deep said, you also need a larger orifice fitting in the master cylinder. You can either order one, or drill out your existing one when you remove everything to remove the residual valve. The orifice screws onto the back of the master cylinder.

So it goes MC > orifice fitting > solenoid > brake line

ok thanks

thanks for everyones help. saved me lots of time and hair pulling.

Got one side of the brakes replaced today finally with all the right parts.

Took the MC apart and took that valve out no problem. Now the orifice fitting, that is the last brass fitting that comes out the opposite end of the MC towards that brake. And that comes out.

According to that diagram there is rubber washer behind it does that come out too.

You don't remove it and throw it away, all you are doing is verifying it's sufficient in size. But it depends which actuator you have in the first place. Drum brakes use a smaller orifice than discs. You have to go by the manufacturer specs what it should be for discs.

http://www.championtrailers.com/DISC...ON_ARTICLE.HTM

I don't believe an orifice is necessary with disc brakes . This gives you a minimum size that will still allow good pressure . No orifice for me , I want all the brake pressure and return flow I can get . Quote from Champion Trailers article..... " Also be sure that the master cylinder tubing adapter orifice is bored to a minimum of .0625" . This will facilitate the return flow of fluid to the master cylinder on the return stroke. "