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Discussion Starter #1
Hi,
I just read the fuel filter help thread but I'll take it down to my level... have any of you actual instructions on changing the filter? I've recently heard about air getting into the system, etc. I never had an issue with my 06 TDI but reading about priming makes me a little apprehensive as I never primed my other. Was I just lucky? I want to do this right so I'd need better step by step help if somebody is willing to offer.
Thanx-
Chris
 

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How many miles are on the car? I wouldn't change it early just for the sake of it. FYI, diesel is a lubricant so a few air bubbles won't damage any fuel pumps. If it has lots of air or is run dry, I would think that could cause some damage.
 

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I did my fuel filter change on my '10 Golf TDI recently, it was an absolute pleasure. Make sure you have a VCDS scan tool or otherwise be prepared to jump wires to the primary and lift pump to prime.

As Chitty stated, the major difference between your older TDI and the new one is that the new ones don't run the pumps when the key is turned. That is the reason for the priming procedure. Also, very important to fill the canister with fuel and ensure that the filter is soaked when putting the canister back together.

The issue with priming is mainly that the HPFP in these cars, that everyone seems to be so afraid of, is more sensitive than most fuel pumps to air pockets and contaminants because of the tight clearances and high pressures within the pump that require uniform lubrication and fuel to use for cooling. You will no doubt, even if you do everything right, get a little air in, but you want to minimize this. Anything more than the absolute minimum air pocket could cause a problem with this pump.

Also important to note: The priming procedure has nothing to do with the HPFP. The primary and lift pumps will be circulated during priming to allow air to escape that may have entered the fuel lines to and from the fuel tank and inside the filter housing. The HPFP is mechanically driven off the timing belt, therefore, that pump will not run until you start the car. My car required a little more cranking than usual to start after the filter replacement because of this. I anticipated this, therefore, I cycled the key to start for a few cranks, let it rest, then cranked a little more. No need to cause any more friction in there than you need to.

Also, while you are in there (I believe this is also mentioned in the FAQ) I would look on top of the fuel in the canister (after you remove the cover and the filter) and through to the bottom of the canister after you remove the filter to see if there are any metal flakes. Anything more than a few tiny specs that you may find may be cause for concern and indicate the possibility of an impending premature failure of the HPFP. Mine was clean at 15,000mi, aside from the dirt on the outside of the filter. VW recommends fuel filter replacement every 20,000. I am on a 7,500mi OCI and thats why I did fuel at 15,000 just to keep everything together. Its really pointless for me to shorten these intervals, but I pack on the miles quickly and its easier for me to time it a little short.

Good luck. I changed the fuel filter myself in less time than it takes me to drive to my dealer 7mi away, and I know it was done properly!
 

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Discussion Starter #5
Hi guys,

The link Chitty sent? Great stuff! I'll learn to search thru and find things better, I'm sure. Change it too soon? No, I'm just trying to be ready is all. AND wow, what a description from Golftdi1 ! I appreciate the time you took to write this out and things to look for.
I always remember the first time changing either fuel or oil filters both were a pleasure to do vs. some other vehicles.

Man, I'm sorta sorry I didn't load mine up too. no sunroof like I had in the Jetta and the Dyna? these would have been real nice... any suggestions?

Thanks,

Chris
 

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:D No problem, knowledge is power!
 

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Explain the harm in just filling the canister and cranking the engine when done without cycling the pumps. Obviously, the harm is not to the pumps, since they are being run in either case.
 

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Explain the harm in just filling the canister and cranking the engine when done without cycling the pumps. Obviously, the harm is not to the pumps, since they are being run in either case.
My total guess is that as long as the canister is filled, it shouldn't make much of a difference. None of the pumps will run dry. However, the service manual says to prime the system 3 times. My best guess is that this primes the system to help make any air bubbles less noticeable. I still have no idea why they don't run the pumps when the key is set to ON anymore.
 
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