Touching the truck brakes brings a thump from the play in the telescoping hitch and the brakes applying.
Any way to adjust the play from the surge brakes for a softer application?

 

Could be a worn actuator or maybe something else. You sure the brakes are working? I ask because I have owned several boats with surge and have never had a thump when applying brakes since when you're stopping, you're compressing the actuator. It's always a clunk when going from stopped to moving as the actuator is then released. I've never had a surge that didn't bang on acceleration. Bugs the heck out of me but it's the nature of the beast.

 

My first trailer with surge brakes.
Doesnt back up going up a slight slope with the electrical disconnected. So the brakes work.
I may have to dig into the m/c and see if I can adj some play from it

 

Try bleeding them. Might have some air in there.

 

Mine always give a little thump when starting out. Pretty smooth when stopping though. I've been looking into converting them to electric over hydraulic.