New boat trailer brakes.

[LUMBERLEO]

I'm sure this is a silly question but.....  Picked up my new boat today.  It has hydraulic surge brakes which in not familiar with.   The brakes didn't seem to be working at all and it felt like the truck was doing all of the braking. 

Figured I would just google it when I got home.  Can't find diagram or anything on Google.  Then I read I might to pull a pin while backing it up. 

Anyone help me with what the different pins are for and how they work.  Thx

[Revtro]

The pin is for backing up.  You put the pin in when you are going in reverse so that the hydros don't function.  If you leave the pin in while trailering the brakes won't work because the pin will prevent the piston from compressing.  So pin out when trailering, pin in when backing up if needed.  I never needed to put the pin in when launching as long as I didn't gun the truck.

When I say pin, I am referring to the weird shaped key thing you have in place in the picture.  You gotta remove that for the brakes to work.

[21XDC]

These links should help...

http://www.ufpnet.com/Actuators/tabid/54/Default.aspx

http://www.ufpnet.com/DiscBrakes/tabid/57/Default.aspx

[LUMBERLEO]

Got it.  Thanks guys that makes sense now.

[Firefighter Jeff]

Hmmm mine doesn't have the pin.  But I know if I use a 4 prong flat wire harness it won't back up.  A 5 prong senses backing up when vehicle is in reverse and a solenoid keeps it from compressing.

[Revtro]

The pin is actually only intended for use when you don't have a 5 wire system to engage the solenoid.  Or when you have a short or something and you need it to be able to back up without compressing the piston.  Gotta say, I sure miss having those kind of brakes.  They always worked great on my old BassCat but now my trailer doesn't have brakes.