L300 4D56 – New primer and genuine Mitsubishi fuel filter, but still leaking at the seal
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Hey everyone,
I replaced the fuel primer with a brand-new one and installed a new genuine Mitsubishi fuel filter. The filter has one rubber gasket, and the underside of the new primer appears to be bare metal.
When I bleed and prime the system, the primer gets firm, but if I keep pumping, a small amount of diesel starts coming out around the joint between the primer and filter. It's not enough to drip, but obviously it shouldn't be leaking.
When I first started the van, it idled fine. However, when I used the throttle lock to hold the revs around 1,200 RPM, the engine started surging up and down on its own roughly every 7 seconds.
I'm wondering if the leaking seal is allowing air into the fuel system and causing the surging, or if something else could be going on.
Has anyone run into this issue? Does the primer-to-filter joint require a separate seal, or should the rubber gasket on the filter alone be enough? I'm trying to figure out whether I have the wrong filter, a faulty new primer, or a sealing issue. The filter seems to be the right size and fit. Screwed on no problem aswell. What am i missing here?
Any advice from someone familiar with the L300 fuel system would be appreciated. Thanks!
Edit: is it possible to buy just the filter rubber seals seperatly?