Hi,

last year i replaced one of my pipes ('82 westy, gas conversion). The pipe
was leaking, weeping through tiny pinholes, where it went over the gas
tank.I only noticed it after i had dropped the tank for rubber grommet
repair etc. BTW, I use orange coolant, sure shows the leaks clearly!

I used 1.25 inch ID coolant hose (Gates, got it at a local heavy
equipment/hydraulic supply place, very tough, made for the pressures and
temps involved), cost around $50. This size hose is larger than the stock
metal pipes and would slip right onto the metal "hose barb" at the radiator
and I used an appropriate sized hose barb nipple to connect to the rubber
coolant hoses at the engine end.

I had to cut the old pipe in half to get it out (angle grinder). Interesting
to see how uncorroded the inside of the pipe was. Apart from the ends and
where it was leaking, the interior of the pipe looked brand new.

The leak occureed on the seam of the pipe (pipe "rolled" into
shape then welded). I guess that inclusions/impurities in the weld was the
problem. GOing out on a limb here, but I bet that many pipes rust from the
outside in, after the proctive paint/undercoating is lost the pipes would be
exposed to the elements. Inside should be good if the coolant is replaced on
schedule.

The new hose was heavy and a bit awkward to install. I routed it along the
same path as the old hose. The incresed diameter (OD) of the replacement
made some spots a tight squeeze (wouldn't be able to run a hose replacement
for the other pipe along the same path).

After a year and a half all is well.

alistair