I used marine coolant hose to replace one of the main lines on my '82
westy (I4).

You are correct in that you need to support the hose under the van.
As I still had one original steel pipe still installed, I simply
cable tied the new hose to it.

But, the main disadvantage is the larger diameter of the hose. It
would have been impossible, if i had been replacing both hoses, to
route the rubber hose through all the same cross frame holes as the
originals went.

Its not a deal breaker, as you can easily bend the rubber hose to go
(under IIRC) around the frame members.

Oh and one more thing, your arms and hands  will be tired after
wrestling that length of marine hose under the van.

cheers

alistair

On 6-May-10, at 7:22 AM, Dave Mcneely wrote:

But, others have said they use coolant hoses to replace the pipes.  I
assume this requires some simple engineering to keep the hoses from
sagging, but they seem much cheaper to buy, should convey the fluid
with the same efficiency, and are engineered for the purpose of
carrying hot coolant.  Is there a real reason not to use them?
Thanks, DMc