Yes mine where damaged during the first test drive before buying the class C. Then we had to install another leafe spring on each side to bring up the rear of the coach.
I always had a problem with those valves leaking. I tried cleaning it up as best as I could, then sanded the fiberglass, mixed up epoxy, and had some fiberglass standing by. Applied the epoxy, fiberglass batt (about 8" square) and more epoxy. Let it all harden, and hopefully it stopped leaking.
Sold the RV a year later, and bought a Bounder with enclosed tanks and 18" bumper to ground clearance! Holding tank valves are now inside a basement compartment 18" off the ground, and the tanks are sitting above the frame rails, where they should be!
You might also consider a spring upgrade. It really helped out on our 85 GM 3500 RV. It brought the whole rear end up a lot, and it stopped dragging as we left the gas stations too. Ours was done in Las Vegas, at a spring shop. Look for a heavy truck repair facility near your home. I know they have a lot of them out in the valley. I think that our cost was only in the $300 range, back in 1994.
Have fun camping!
Fred.
