Rear wheel brakes could be adjusted too tight so that they drag all the time
Rear wheel brakes could be only ones getting voltage and doing all the braking or majority of braking.......bad connections/wring to front axle brakes OR front axle brakes NOT adjusted
G614 tire blowing
Look like new BUT what is the DOT date code......4 digit number on inside sidewall
EX: DOT U2LL LMLR 5107
5107 date code
51st week of 07
New to you trailer........are tires OEM and 2009 vintage??
IF so they are 7 yrs old and you are luck it blew while stationary
Mine on 2007 5vr blew while traveling. 3 1/2 yr old.....Goodyear had some BAD batches 2006/2007
$3000 damage....Goodyear paid
So check the Date Code.
Might need all new tires plus spare
IF so
Check out Sailun S637 ----'G' Rated tires (4080#/110psi)
Alternatives to Goodyear G614s
Good reviews/ratings.higher capacity and CHEAPER