VW T4 Forum - VW T5 Forum banner

Fitting a fuel filter

11K views 9 replies 4 participants last post by  Dan 3222's  
#1 ·
Sorry, this is probably a really dumb question, but I'm new to tampering with anything engine related so here goes.

I've brought a new fuel filter, I'm happy enough with connecting it up / fitting it. But I was under the impression that you need to fill it with diesel before fitting it? It doesn't look like there's any way of getting the diesel in. Here's a pic.

Fuel filter by astevo1983, on Flickr

Am I just meant to get a really small funnel and fill it up? Or is it not necessary to fill it with diesel before fitting it?

My van has a starting problem that sounds like it's likely to be because of the fuel draining back in to the tank, so no fuel is getting to the engine when I try and start it. So I want to change the fuel filter and see if it helps the problem. But if the pump in the fuel tank is responsible for the problem, fitting a fuel filter full of air / disconnecting the fuel filter and allowing all the fuel to drain out the lines might make the problem bad enough I'll never be able to get fuel to the engine? What's the best way to go about this?

Thanks.
 
Discussion starter · #8 ·
Thanks everyone.

I'll have a go at it at the weekend. Sounds like running the engine for a bit to get the fuel system working nicely before fitting the primed filter is going to be the least likely to cause me stress way of doing it. I've got some tubing, should be able to pick up a funnel somewhere, and prime the filter like that.

The comments about running the lift pump using VCDS / cycling the system a few times to prime the filter. Sounds like that might be a good way to figure out weather it is the pump in the tank that's the problem or not? If I disconnect the line from the fuel tank to the filter and cycle the engine / run the pump with VCDS I'm guessing fuel should squirt out if the pumps working? Is that enough to confirm weather the pump works properly? Or would I need to test the pressure the pump is putting in the line? It would be nice to be able to confirm the pump is / isn't the problem without having to get a new pump and drop the tank and all that to fit it.