safety bar release cable

Hi All - I recently purchased a 1972 Traveler. It worked great (like I drove it from Colorado to Philly and back with no problems at all) until this past weekend when we were camping in the mountains in Colorado. When we went to pack up, the trailer wouldn't go down. It feels to me like...

We're trying to lower the Hi-Lo but the cable won't release. It seems to come out and have a crimp that holds a loop for pulling, then the remainder is pushed back in the hole. Hopefully it shouldn't be attached to something too. If the hydraulic fluid is low will it still release and lower...