Replacing diesel pump-to-filter plastic hard lines

Hi-I installed a new style hand primer pump today- Thats the good news, bad news is when I disconnected the fuel line fitting near the primer pump, the hard plastic like fuel supply line coming from the main fuel filter snapped. That doesn't surprise me since it's probably 30 years old, and all these lines now seem as hard as a rock/brittle.They attach to a fitting having 3 or 4 'barbs' on them and do not use hose clamps at all as they are probably not under much pressure. Is it necessary to use exactly this type of line to replace these, or can I just use diesel fuel rated hose of the correct internal diameter to replace them, or would they then not stay on the barbed fittings tightly. Can hose clamps be run on the barbed fitting ends with alternate type rubber style fuel line. Does anyone know what the correct internal diameter of these lines is? Thanks!!

Forums

Diesel Engine Specific Aid

Chassis Model Number

W115

Replacement options

I have never really been completely successful at just trying to replace the clear hard plastic hoses. The ends have to be heated to get onto the barbed nipples and if not heated just right they will kink or leak. New replacements are available that come with the fittings attached. I also have some good used ones in stock.

As an alternative you can use fuel grade rubber hose with a 8 mm or 5/16 inch inside diameter. But to use this size hose you MUST leave the plastic on the barbed end of the fitting (just cut the old hard line off flush with the very tip of the banjo fitting). This will give you the spacing you need for the rubber hose to fit tight on the nipple. If you use our German hose clamps the rubber will seal tightly against the old plastic and not leak.