There have been a few companies experimenting with air powered disk brake systems for several years.
The problem has been getting the the friction surface large enough to 1)actually stop the rig and 2)disipate enough heat fast enough to prevent failure.

We looked at ordering Volvo's but we have 3 drivers that are 6ft 6 inches in height or more and the bed is right up against the drivers seat in the big bunked Volvo's and the freightliner's have more room to move the seat mount back. So that palyed a big part in our decision.
Wick

.....I have 4 wheel discs brakes and steel rims on my MDT Wrecker...electric over hydraulic by Hayes...no problems but EXPENSIVE to repair/replace.....geofkaye

Congradulations, Warpath, on the new rig. From my experience, the one thing that I did not have problems with was the truck. I have an '03 Columbia with the Mercedes and 12 speed freedom transmission. Knock wood, it's been 2yrs, 2 months and 44,000 miles. I saw the pics of your truck. Take a look at my post at conversions-general, height/length issues. Let me know when you damage the bottoms of those back doors. I bet you won't be able to go more than a few months before you have to go down a driveway and over a crowned street and drag the back end. I'm not wishing you bad luck. I'm simply trying to call attention to a situation that should be remedied while the conversion is still on paper. Good luck, maybe you'll have different fortune than myself or the conversions that I've seen on the road for a while. The same door manufacturer that Showhauler uses now has a design for a rear door that is tapered so that you can get some air between the asphalt and aluminum.

I picked up my unit this past week. Made a stop at the Meremac caverns in MO. What fun.

2006 United Spec. 24'box on Volvo VNL 420/Cummins ISX 475/1650/freedom 12.

1) no need for more power.
2) quiet, and smooth.. esp. with the air ride seats.
3) 10k diesel APU keeps the two AC'c running full time without a whimper.
4) stopping is great.. better than my highline Monaco. Especially, with the engine retarder.
Brakes are also larger.
5) 27,980 lbs with 100gal water, 24gal propane four people and assorted gadgets.

Way too much fun passing Pickups with trailers on the westbound climb from Needles.

Wheel spin indicator lights up if not carefull during radiused onramp approachs to highway.