It's done and not as bad as I thought--but not an easy, clean or quick task. Lots of crawling under the mh and working in cramped spaces near the front wheel well and around the rear axle. Oh and did I say dirty from all the oil. It took about 8 gallons of hydraulic oil to refill the system!
What I did was to use 1 1/4 inch plastic electrical conduit and 1 inch flex plastic pressure water hose purchased from Home Depot to run the new ps hose inside.
I routed the conduit outside the main frame beginning about even with the front tire drivers side to about half way through the propane tank compartment. Then I angled down at 45 degrees to run the conduit along the inside of the approximately 1 1/2 inch box structure supporting the bottom of the basement under the mh. At the rear of the 1 1/2 inch box structure near the rear wheel, I used the plastic water hose to snake up along the spring structure to the frame and back to the hydraulic control box just behind the rear axle.
I supported the conduit and hose with large wire ties used for bundling groups of wires. I secured the conduit and hose to the existing bundles of wiring and hoses, the frame, the 1 1/2 square structure and anything else I found that would work. I did bend some 1 1/2 inch metal conduit clamps so I could clamp to the 1 1/2 inch square structure to support the hose. I used a rubber 1 1/4 inch coupling for joining the hose and pipe together.
Once the pipe and hose were installed it was relatively easy to push the new ps hose through to the rear of the unit. I did not glue the conduit, 45 ells or connect the hose together until after I pushed the new ps hose into position and connected the respective ends of the new ps hose. I used foam insulation to seal each end of the conduit to prevent water, dust, etc. from entering.
Spartan says the hose is originally 32 ft long for our unit. My new route required 31 ft 4 inches of hose. Our local hydraulic supply shop made up the hose to Spartan's spec, Spartan is always great to work with and supplied the specs for the hose and fittings within an hour after I placed the call to them.
The mh has now been driven back to the storage lot and all our neighbors are happy.
Spartan did say they repair this problem by drilling a hole in each end of the basement and routing the new hose through the basement. When I looked at all the water heater, holding tanks, fresh water tank, etc that I would have to fish the hose through, I chose an outside route.