Are the 2 heater hoses coming from the engine each one continuous hose going to the heater core?
John,
If your water heater has the optional heat exchanger from the engine, your heater hose leading forward probably makes a detour to the water heater and then forward. You probably also have a booster pump at the back for the heater with a switch on the dash.
If you have hot water while driving down the road with the water heater turned off, then you have the internal heat exchanger.
Pierce
Correct. Most have one hose to the Y to the water heater and then to the dash heater then the other one is all the way back.
In 99% of the cases, the deterioration is only in the part in the engine room-- the rest is not exposed to heat, oil, fuel road debris, more likelihood of chafe, etc.
So, if the back section is bad, replace that section ONLY using a good quality barb to barb fitting where you splice into the long hoses.
Just a couple of days ago I discover where the Y's were in my heater hose that has the branch that leads to the water heater (per the comment from Pierce). They are directly above the forward end of the transmission (closest to the universal joint) sitting on top of the cable/hose runs that go from front to back. Of all the times I have crawled in and out of all the nooks and crannies of my coach for the past 16 years I finally pushed the cables away in the right spot. They are just a simple plastic Y (and not a TEE) with regular worm drive clamps on them. It makes sense Foretravel put them there (versus in the basement) so they can be serviced and any leak wouldn't flood the utility bay with coolant.
I replaced mine front to back in my 91 with the exception of the 2 going to the water heater heater. There was no way to access them without removing the water heater. The portion of the hose that was in the chase looked as good as what I replaced it with. Gates Green Stripe heavy Duty Hose. I wouldn't have spent the time doing that section had I known it was in such good shape after 23 years.The back sections where the engine is were the worst areas as Brett Said.
I did put 2 shutoff valves on the engine so in the event of a leak I can just close off those lines and keep on getting on and fix them .