Fuel Filter Replacement

[Seatdriver]

Hi,

I have read a few threads on replacing the fuel filter but I have the following questions.

 

On a 1.9 Td1 Sharan 2003

 

Is the system under any sort of pressure and do you need to allow to discharge before removing any of the 3 pipes (especially the one with the clip as this is almost certainly the fuel feed from the tank), another is a return to the tank (i presume), and the third is (feed to injectors again this is a guess)

 

It was mentioned in a thread that the new filter needed filling with diesel, is this absolutely necessary, never done this before with a petrol fuel injection system.

 

On my old Ulysse there used to be a water drain! to remove water filtered out of the diesel, as there is no such beastie on the Sharan am I to believe that the filter just slowly fills with water and hey preso bad running occurs eventually as you are effectively trying to run a car on water with a bit of diesel in it!

 

many thanks in advance

[Steveenduro]

No need to remove any pipes. The plastic T piece that the pipes are attached to comes away from the filter after removing a spring clip. It is not under pressure. I would fill the new one with fresh diesel to save having to prime once re-fitted.

[Bigjeeze]

If you look on the bottom of the filter you will find the water drain .

[galaxytony]

if there are three pipes one will be the return back to the tank which means that you dont have to prime/refill the filter as this will happen automaticly as any air will be returned back to the tank

[Seatdriver]

Hi again,

 

Yup there are three pipes (1.9tdi 2003 Sharan), I have a new filter from main agent and there is no sign of any drain nor is there one on the one fitted to the car presently (again an original VW part). On top of the filter are 3 pipe outlets that the fuel lines attach to, one is clipped down, the others have a clip and are push fit/clip only.

 

Perhaps the filter differs on other versions.

 

Will post back when job done!

[Bigjeeze]

If it is a Bosch filter - and I am sure it should be - the drain is a white plastic wheel on the bottom of the filter.

[Seatdriver]

Hmm

 

Methinks are we discussing the same thing here?

 

The fuel filter on a 1.9tdi 2003 Sharan is sited on the right hand end of the engine (opposite the pulleys) at the back effectively looking at it you have the battery on your right and the engine on your left. The part is not Bosch but it has the VW stamped on it in big letters.

 

The new filter is a solid can, looks like an inverted oil filter, with 1 hole and 2 male pipes at the top. There is no wheel, or drain of any sort. The part is a genuine VW stock item.

 

Is there another filter I should know about?

[Steveenduro]

That's the fuel filter alright, but I'm pretty sure it should bave a drain screw for water underneath. Have you got the right part?

[Seatdriver]

Yup its the right part 7MO127 401 A

 

If you check TKpeter Aug 29 2006, 13:37:31 it is identified in this list, and its what on the box VW gave me.

 

Conclusion; There is no water drain on the fuel filter.

[strouf]

There's more than one kind of fuel filter that fits the car, bigger or smaller, with or without water trap, depending on the climate conditions, use etc. You could go to a car filter (or auto parts) dealer and buy one which has the same shape and threading, but it's slightly bigger and has a water drain.. I would recommend the German "Mann Filter". Consult their catalog ..IIRC it's the WK842 type... Edited November 2, 2007 by strouf

[Seatdriver]

Thanks strauf for the clarification

 

Is there a problem with the VW part, am I correct to suspect that the original type will slowly fill with water and this eventually begins to mix with the diesel going to the injectors? eg diesel water mix = lumpy running

 

Thanks

[strouf]

Hello again, sorry for the late reply!

 

Hope you have sorted this out . The online filter catalog :http://www.mann-hummel.com/mf_prodkata_eur/index.html?ktlg_page=1&ktlg_lang=1

 

Even without a water drain, diesel will not mix with water .Provided that you change fuel filter regularly you will be ok. The design of the filter and its piping is such , that water (beeing heavier than diesel) sits on the bottom of the catridge, while diesel is sucked into the pump from the top. But a larger filter with water drain can be in service for longer period .