If one section of a steel line is corroded and leaking, it is likely that the rest of it is in similar condition--assuming it is all uncoated pipe. Uncoated pipe tends to corrode at the same rate, whereas a coated pipe ( some sort of corrosion coating) will concentrate all the corrosion at the weak point of the coating. The rest of the pipe may be OK.

If you want to do it once, go ahead and do it right and replace it all.

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1982 300SD " Wotan" ..On the road as of Jan 8, 2007 with Historic Tags