Independent Brake Wire Feed Upgrade
I followed John's procedure to do the same upgrade on the 2499. These wires really don't last that long--I'm guessing the 2499 was only 5 years old, but towed about 5000 mi./yr. Higher mileage would induce more chaffing. As well the bundle of wires with crimp nuts, that feed into the brake drums, have no support from bouncing around over bumps. That's actually where my wires broke, but I decided to do the whole re-wire figuring the wires inside the axles weren't going to last much longer anyway.
Be sure not to buy too small plastic tubing. Pushing 8' of wire into the tubing is a lot more difficult than testing how easily 1' slides in when you're in the store.