Hi Steven,

I replaced two of the 3 lines when I replaced the pumps on an 1987 420. I couldn't get the main line off, otherwise I would have replaced that too, but then I replaced 2 pumps and the lines made not much difference. I pinched the old one without problems. Considering the system is under quite some pressure, the lines need to be quite strong. Then again, if you worry about them, I'd replace them.

Regards

Reinhard Kreutzer