PeachParts Mercedes-Benz Forum - View Single Post - Removing plastic fuel lines

jay_bob · #6 07-06-2015, 07:17 AM

You can change the SOV o-ring without removing the IM. The washer bottle can be drained and moved out of the way which allows access to the SOV. The washer bottle heat exchanger can be removed without breaking the coolant lines.

I would follow the fuel path as described above and see where you are getting air. Note there are two independent paths in the fuel filter housing, the pre-filter and main filter flows do not mix. The o-ring on top of the pre-filter is another known leak point. Also the clamp that holds down the inlet hose to the pre-filter gets tired and does not provide enough pressure to keep the o-ring seated. They really should have put 2 bolts on that clamp.

Remember the lift pump pulls some serious vacuum (enough to collapse the tank if the relief vent is plugged). In fact the pressure on the discharge side of the fuel pump is still below atmospheric. This means if you have a leak it will admit air instead of leaking fuel.