Good day everyone hope your volla is doing beter than mine.
I have a Jetta4 1900 tdi and its fuel line keeps on drawing air i have replaced line from tank to filterhousing and to&from the pump still suck air so i want to swap filterhousing using one from a TDI Caddy that use s cartridge so my question is does the Caddy use a feulpump or not? And if so where in the line has it been installed.
Help would be great thanks.

The caddy has an intake fuel pump.

Not sure on the fuel filter setup in a MK4, does it have a manual lift pump on the filter housing? Or if not, does it have the black plastic T-piece on the return line?