I would hook the rig up and go for a drive. In a parking lot or a little used road I would take my foot off the acelerator and use the lever on the brake control to bring the entire rig, truck and trailer, to a stop.
Testing under controlled conditions works better than feeling uncomfortable after a panic stop.
Wnen comparing braking distance of an unloaded tow vehicle and tow vehicle with RV attached it is normal for the distance to drastically increase. You won't be able to stop on a dime. Just think about how much distance it takes for an 18 wheeler to stop. Same concept just on a different scale. Some people call it defensive driving, I call it prepared driving. (Always looking ahead and keep it slow.) Of course proper maintenance and adjustment of equipment is part of being prepared.
As far as tesing brake engagement while unhooked, there are a couple of pins on the 7way plug you can connect together to test for brake action. I can actually hear my brake shoes hit the drum. (Can't remember the pin numbers to connect. Would have to look it up.)
I know you asked if there was a way without hooking up. In my opinion, no, not really.
I too would hook up and go for a ride. go to a parking lot, deserted road, wherever there is litte traffic and do as other suggest and manually apply trailer brakes. Pulse them enough to get them warmed up. then stop, and "hand test" the warmth of each wheel hub. they should all be about the same temperature. This will let you know that they all are working, but not necessarily adjusted correctly.
I found that my rear axle brakes were not working, and after further diagnosis, found I had a bad wiring connection between the front axle and rear axle brake wiring. I cut/soldered the connections this time, and now have all 4 wheels stopping.
As for adjustments, my trailer has manually adjusted brakes. I hook my trailer up to the truck, and drive each wheel up onto a low ramp, one at a time. this will cause the other wheel on the same side to come off the ground. You can then do your brake adjustments, and at the same time, pull your emergency brake cable, to see if your brakes are engaging. In all, only takes about an hour to do all 4 wheels.
My brake controller adjustments went from running at 9.5 fully loaded to 4.5 fully loaded. I wish my trailer had auto adjusting brakes, or were disk brakes.
* This post was
edited 06/06/12 06:14am by djousma *
'04 Layton 2940 30' GVWR 9900#
2016 F350 Lariat 4x4 FX4 SRW CC SB 6.7 Magnetic Metallic