Diesel Fuel Filter Problem

[2musty]

Hello,

I have just serviced my 2004 Passat 130 TDI and replaced the usual filters and oil. As i removed the diesel fuel filter i took off the control valve which sits on top of the fuel filter and replaced the two rubber rings (blue and black). As i have gone to put the control valve back on the new filter, it does not fit as tight as when i took it off the old filter. As i started the car when all the pipes had been secured it started to leak around the control valve when the system became pressurised. I tried swapping the filter with the old filter and replaced the washers but to no joy. Against my better judgment i bought the filters from Euro Car Parts and the diesel filter is made by Bosch, Could this be the problem as i did not by Original Parts?. If anyone has had similar problems could you please help.

Cheers Imran

[Col]

I've used Mann and Bosch fuel filters on mine with no problem.

In fact Mann probably make them for VAG.

You may simply have a duff filter.

You have obviously carefully checked the seals to see if they are twisted and wet them with diesel before inserting into the filter?

[2musty]

Hi,

I have checked the rubber rings and wet them before putting them back into the filter, but still no luck, I even bought another filter from Halfords just to check if it was not a duff filter and still the same problem. The control valve does not fit tight and is still loose even when the black clip is in place. I have replaced the rings with no joy.

Do you think i have the incorrect rubber rings supplied?. When i changed the rings and tried out the old filter that leaked aswell. What about the control valve, is that problematic?

Cheers

Imran

[Col]

I can't see what could be wrong.

The bit in the filter that the valve pushes into is a simply casting or at least that is how I remember it. What I'm getting at is there cannot be anything that could be left behind in the old filter? (I'd check the old one).

Next step would be a new valve / stat.

[2musty]

Yeah,

Im gonna head to the dealers in the morning and get an original filter with new control valve, hopefully this should sort out the problem, Im thinking that it may be the control gear or rubber rings, as it is not a tight fit, that may be the issue as i have tried another new filter with the same problem. Either way I will keep you posted.

Thanks for the help

Imran...

[2musty]

Fellas,

Just to let you know i went to the dealers and picked up the control valve at a cost of £15 and a original diesel filter, The two went together without any bother and was a tight fit. started the car no probs. The chap at the dealers stated the control gear is a common problem because when removed it can cause a hairline crack, which when pressurised will leak. To me the original filter is a different company than Bosch, Hengst and Mann. The control gear was a loose fit in these filters but the original, No probs.

In my opinion your better off spending the extra £10 than having the run around later.

Cheers

[snapdragon]

Thanks for the useful info! Well done.

[Dave Elcome]

In fact Mann probably make them for VAG.

Actually Mahle make the filters, although they own various other companies now and still use their brand names. I know this to correct as my brother in law works for Mahle, and as a result I get free filters.......... bonus.

[sherlockuk]

Hi,

I have checked the rubber rings and wet them before putting them back into the filter, but still no luck, I even bought another filter from Halfords just to check if it was not a duff filter and still the same problem. The control valve does not fit tight and is still loose even when the black clip is in place. I have replaced the rings with no joy.

Do you think i have the incorrect rubber rings supplied?. When i changed the rings and tried out the old filter that leaked aswell. What about the control valve, is that problematic?

Cheers

Imran

I had exactly the same problem about a year ago with a filter bought from GSF... The O rings were too small.. I popped into my local VW garage and explained the problem and they gave me a set of O rings free of charge.. I was very suprised...

Glad you sorted it. Damn GSF.. So good normally.