Fuel filter O-rings -- important!

caruna

New member
Joined
Aug 12, 2007
Location
New Hampshire
TDI
2002 Golf
So I had to break down about 6 times before I finally got it through my thick head ---
ALWAYS put on new O-rings when you pull the return line port (is that what it's called?) off the fuel filter. Put in new O-rings EVEN if you just pull it off for a second to see if there's fuel in the filter.

I kept breaking down because of no fuel getting to the injectors, caused by air being sucked into the system somewhere. The best my local mechanic could tell me was to go to VW and buy a proper filter rather than the Wix knockoff sold at the parts store. Finally it occurred to me that the Ace Hardware in town sells O-rings. I now carry a little bag of them, and I haven't had a problem since, regardless of filter brand...
 

Naimanator

Veteran Member
Joined
May 14, 2007
Location
Davis, CA
TDI
Silver 2002 Golf GLS TDI
You know, it's funny... I changed my fuel filter about a month ago and didn't realize that there were o-rings I was supposed to change. I haven't had any problems yet though.
 

owr084

Top Post Dawg
Joined
Oct 20, 2004
Location
Northern Virginia (NoVA)
TDI
Passat GLS, 2005, Stonehenge Gray
What's worse is swapping the the sending line from the tank to the filter and the return line to the tank from the tee fitting :eek::eek::eek: Definite no start conditions...

caruna said:
So I had to break down about 6 times before I finally got it through my thick head ---
ALWAYS put on new O-rings when you pull the return line port (is that what it's called?) off the fuel filter. Put in new O-rings EVEN if you just pull it off for a second to see if there's fuel in the filter.

I kept breaking down because of no fuel getting to the injectors, caused by air being sucked into the system somewhere. The best my local mechanic could tell me was to go to VW and buy a proper filter rather than the Wix knockoff sold at the parts store. Finally it occurred to me that the Ace Hardware in town sells O-rings. I now carry a little bag of them, and I haven't had a problem since, regardless of filter brand...
 

thermopylaetech

Veteran Member
Joined
Jan 16, 2007
Location
Accord NY USA
TDI
2005 Jetta Variant TDi/PD
The arvin meritor "purolator" branded filters I use come with a baggy with more then enough little o-rings and I change them every time, just like the o-rings on the oil filter. The last thing I need is hot diesel spraying around!
 

KS97Passat

Veteran Member
Joined
Mar 7, 2005
Location
Norwich, KS
TDI
Passat sedan, 1997, maroon, 129k mi.
Can someone report the size of these o-rings so that I can get some from my local "o-ring store" (I may hold out for viton material too)? For some reason, Caterpillar doesn't include these with the retrofit filter I buy from them. :p

I have a friend whose car I suspect has this sucky problem. He's getting lots of bubbles in his clear fuel line (A4 - manual transmission) and the car is a little slow to start.
 
Last edited:

Ron 33

Veteran Member
Joined
Oct 17, 2000
Location
South Carolina
TDI
Y2K Jetta GLS Atlantic Blue, Manual
Wrong o rings will stop you dead in the road.
Happened to me, fun meter was pegged.
The last fuel filter I installed was a Purolator. I did not notice the size (diameter) of the o rings until after the mishap. After a mechanic spent 4 hrs troubleshooting, he changed the fuel filter, and we were running again.
After getting home I found the T valve o rings were smaller than the new o rings on the new T valve I got to carry as a spare.
No more Purolator fuel filters for me, I suspect the filter and the o rings.
 

Lefty

Veteran Member
Joined
Oct 21, 2005
Location
Lazear,Colorado Population 60
TDI
Jetta, 2000,Green GLS
That's funny, last year I changed my filter in a Walmart Parking lot and dropped the mickey mouse clip. I never found it nor did I have the o-ring. I went to an Ace Hardware and got an o-ring and then used a paper clip to hold the T down until my daughter sent me a new one from Denver. Ace is the Helpful hardware place to go. Oh, and when you change it next time, use a string on the Mickey mouse clip in case you drop it.
 

greengeeker

Vendor
Joined
Feb 8, 2006
Location
Cambridge, MN
TDI
2002 Jetta GLS
caruna said:
Put in new O-rings EVEN if you just pull it off for a second to see if there's fuel in the filter.
Keep this in mind when you buy a filter with the thermostatic T pre- installed from one of the trusted TDIclub parts suppliers. Yes, you will be on your own for new o-rings if you pull it to pre-fill with diesel. :cool:
 

TDIfor

Veteran Member
Joined
Aug 20, 2003
Location
Logan, Ohio
TDI
'02 NB Double Yellow
Warning, warning, Will Robinson....

Bought a VW fuel filter from the dealer. Had MOGolf install it along with other work. He questioned where I got the filter, and where I got the O-rings. He didnt like the look of the O-rings, but swapped them out.

Fuel filter was installed, filled with fuel, Mityvaced, everything. Engine started and died within 5 secs.

Bottom line, the O-rings were bad, and had broken upon reinstallation of the T-fitting. Ended up re-using the O-rings from the old filter.

So, VW has <Im shocked, shocked> a series of bad parts kicking around right now. Maybe the O-ring issue has sorted itself out by now, but look at the O-rings. Now, I dont know how to tell a good O-ring from a bad one, but if you install a VW fuel filter, and the engine dies on you, you may have been bitten by a flaky O-ring.
 

unL33T

Veteran Member
Joined
Jan 23, 2006
Location
Eden Mills, ON, Canada
TDI
'01 Jetta GLS TDI
I'm pretty sure I didn't see or change any O-rings when I did my fuel filter... but that was awhile ago so I might just be absent-minded.

Now I'm worried.
 

Darth Bug

Active member
Joined
Sep 4, 2007
Location
Olympia, Washington
TDI
2002 Beetle GLS
so did any one want to post the size or the o-rings i should get at ace. i'd rather not guess and then wait for a friend to show up to drive back.

stupid new beatles and their fuel filters being weird, and the fact that i didn't know that i could take out the whole assembly to get that stupid butterfly clip back on there. stupid no room. but i love the compact size.

any help would be great, thanks.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
The VW part number for the fuel filter "O" rings is 1JO 198 247 but when I tried it on 1stVWparts.com or worldimpex.com nothing came up...

[EDIT: tdiparts.com does show them in the catalog... $2.50 http://www.tdiparts.com/catalog/product_info.php?products_id=476 ]

Yuri.

PS: since there are 2 different-colored ones in the OEM package, does anyone know what the actual difference is between the blue and black ones ??
 
Last edited:

Dimitri16V

Top Post Dawg
Joined
Jan 30, 2005
Location
DE
TDI
01 Golf, 04 Golf
I used the old O-rings twice , no leaks. Be careful with O-rings from Ace
 

20IndigoBlue02

Top Post Dawg
Joined
Aug 22, 2001
Location
Was North NJ, now SoCal
TDI
2002 Golf TDI-- deceased
KS97Passat said:
Can someone report the size of these o-rings so that I can get some from my local "o-ring store" (I may hold out for viton material too)? For some reason, Caterpillar doesn't include these with the retrofit filter I buy from them. :p
If you bought a Cat fuel filter kit from LanduytG, then the OEM ones will not work. It will let a lot more air in.

you will need a "AS568A-904" sized O-ring which is ID: 8.92mm & CS: 1.83mm.

If you order the CAT filters from LanduytG, he supplies you with replacement o-rings.
 

paramedick

TDIClub Enthusiast, Vendor
Joined
Jul 29, 2001
Location
Versailles, Kentucky
TDI
2015 Audi Q5 TDI, 2000 New Beetle
20IndigoBlue02 said:
If you bought a Cat fuel filter kit from LanduytG, then the OEM ones will not work. It will let a lot more air in.

you will need a "AS568A-904" sized O-ring which is ID: 8.92mm & CS: 1.83mm.

If you order the CAT filters from LanduytG, he supplies you with replacement o-rings.
Nope, the factory O rings will work just fine. They are all I use with my CAT filter.
 

20IndigoBlue02

Top Post Dawg
Joined
Aug 22, 2001
Location
Was North NJ, now SoCal
TDI
2002 Golf TDI-- deceased
I tried the OEM O-rings on mine (with a new thermostatic tee)... they leaked in so much air, it took a while to get it started (I'll clarify... after install of the new tee... it started up fine; the next morning it didn't).

The ones greg supplies are larger, that's why it can be a pita to install them, because the fit is so tight.
 
Last edited:

scurvy

Good Ol' Boy
Joined
Feb 21, 2006
Location
Chicago IL USA
TDI
2006 Golf
20IndigoBlue02 said:
If you bought a Cat fuel filter kit from LanduytG, then the OEM ones will not work. It will let a lot more air in.
paramedick said:
Nope, the factory O rings will work just fine. They are all I use with my CAT filter.
I concur with paramedick. The ones sent with my Cat filter were too large and were an absolute PITA to try to make fit - so much so I cracked my thermostatic tee fitting. The OEM o-rings made the replacement tee slip right in with no problems and no leaks. I appreciate Greg sending replacement o-rings but I won't be using them.

scurvy
 

fritz26363

Active member
Joined
Nov 13, 2003
Location
Columbus, OH
TDI
Silver 2003 Jetta
Agreed, it's a bear to get the T in with the O-rings Greg supplies. Next time I change the CAT filter, I plan on modding the T hole with a countersink to make it easier; Greg's "new design" has the mod.
 

scurvy

Good Ol' Boy
Joined
Feb 21, 2006
Location
Chicago IL USA
TDI
2006 Golf
My filter head has the "new design" allegedly, it's at best a minimal chamfer. Some might call it just an edge break. It is not sufficient to make thermostatic tee insertion easy with the supplied O-rings.

I'm sticking with OEM-sized O-rings for my fuel filter.
 

nylonoxygen77

Well-known member
Joined
Jun 19, 2007
Location
Harrisburg, PA
TDI
A4 1.9 ALH
Ok, so I've been having air bubbles for a while now, and I'm starting to get worried. I have a stream of frothy-looking diesel going from my filter into my IP. I suspect that my thermostatic tee needs to be replaced. I have replaced the o-rings and that didn't take care of the problem. No performance issues. I have a 99 NB. I currently have a purrolator filter installed, and I've replaced the o-rings which didn't help, but since they were replaced I've removed and re-seated the tee probably a dozen times because i've needed to prime the filter, and I was doing some tests.
So, one question - how does the tee work? Isn't it supposed to put hot diesel from the IP back into the filter? I did a test and replaced the IP in the fuel chain with a small 1/12 HP pump and cycled diesel thru the system when it was totally cold. I pulled the tee out with the pump on, and it was shooting the diesel out the bottom of the tee, back into the filter. Is that what it should be doing? Does the tee fitting eventually close and push the diesel back to the tank, once it reaches a certain temperature? Maybe the air's going right back into the filter instead of back to the tank?
-edit-
Replacing the IP with the 1/12 HP pump didn't help the air problem, by the way. I still had air coming from the filter.

I just wanna get this worked out. A new tee is like $40 from the dealer, so I don't wanna get it if the tee's working properly. On the other hand, i'm pretty sure it's the original 9-year-old tee.
 
Last edited:

mrGutWrench

Top Post Dawg
Joined
Aug 29, 2002
Location
Wallace, NC
TDI
'03 Jetta Wagon
nylonoxygen77 said:
Ok, so I've been having air bubbles for a while now, and I'm starting to get worried. I have a stream of frothy-looking diesel going from my filter into my IP. I suspect that my thermostatic tee needs to be replaced. I have replaced the o-rings and that didn't take care of the problem. (snip)
__. I had a bit of trouble with a loose T-fitting on MizLauraLee's '03 waggin, and wondered if it was leaking around the O-rings. I dribbled a little heavy "mineral oil" (from the drugstore) around the area where the T-fitting fits onto the filter. When the clear line immediately showed no more bubbles, I knew that there was a leak in there (although changing out the O-rings hadn't helped before). I got another set of O-rings and put them in really carefully (lubed them, made sure that the T-fitting went in squarely ,etc.) and all was fine.

__. You might try to rule out a leak in the fuel lines, etc.
 

nylonoxygen77

Well-known member
Joined
Jun 19, 2007
Location
Harrisburg, PA
TDI
A4 1.9 ALH
Ron 33 said:
Wrong o rings will stop you dead in the road.
Happened to me, fun meter was pegged.
The last fuel filter I installed was a Purolator. I did not notice the size (diameter) of the o rings until after the mishap. After a mechanic spent 4 hrs troubleshooting, he changed the fuel filter, and we were running again.
After getting home I found the T valve o rings were smaller than the new o rings on the new T valve I got to carry as a spare.
No more Purolator fuel filters for me, I suspect the filter and the o rings.
AHAA!!!!

I too had a Purolator fuel filter. I too spent hours and hours trying to solve the problem. I ordered three sets of OEM o-rings (the blue and black ones) and still had the frothy diesel in the lines. Nothing seemed to help. I was convinced I needed a new thermo-tee - that there was a crack or leak in it somewhere that I couldn't detect. Just before going to the $dealer$, I just said heck with it and put my spare fuel filter in... No more bubbles! The replacement I used was a Purolator as well, so I anticipate a premature filter change again in the near future... but for now the air problems are gone. No more purolators for me either. I will be buying them from tdiparts.com since their prices are pretty good and they'll ship US Postal.
 

fireboy

Veteran Member
Joined
Dec 11, 2005
Location
Wyoming, MN
TDI
04 Jetta GL
Ron 33 said:
Wrong o rings will stop you dead in the road.
Happened to me, fun meter was pegged.
I've had my fun-meter pegged a time or two, Can you over-boost the fun meter?
 

caruna

New member
Joined
Aug 12, 2007
Location
New Hampshire
TDI
2002 Golf
On o-ring size -- I have no idea, but I pulled up in from of the parts store, pulled the port, pulled an old o-ring off, and we compared them by eye. Seems to have worked well.

I and the parts woman couldn't notice any difference between the blue and black rings. It still makes me nervous, though...
 

Honeydew

Top Post Dawg
Joined
Nov 28, 2006
Location
Florida
TDI
13 Passat DSG
Here is the size landuytG recommends from McMaster-Carr. I bought a bag of these a while back when ordering new vacuum lines. Haven't used one though so I can't comment on the fit with the CAT head.
 

brucep

Veteran Member
Joined
Oct 1, 2002
Location
Vermont, USA
TDI
peebs4u2
I beleive that these 2 Orings are DIFFERENT SIZES. Some filter-kits even come with Orings of 2 different colors to make it easier to see the difference between them. (Blue and Black)

It is not the diamator that is different... it is the thickness of the rubber.

When I change my fuel-filter, I am always careful to place the proper Oring in the proper location of the fuel thermostat Tfitting.
 
Last edited:

Creeble

Active member
Joined
Nov 17, 2004
Location
Marin County, CA
TDI
2003 New Beetle
Um, hey. I see this thread is still active, and my '03 NB is not :(

NB's don't have a clear fuel line, so I put one in; about six inches worth. Lots of bubbles. I changed the filter, and things didn't improve -- can't remember if I used a MANN or another brand, but not factory.

I was about to go through the pain of trying to pull the funky little quick-release elbow that goes from the input side of the filter to the line that goes back to the tank (return side doesn't have a detachable elbow), clamp a chunk of clear hose onto the thing, stick it in a jug of fuel, and see if I still have bubbles. If I do, I know it's somewhere around the filter.

But after reading all this, it sure seems like it could be the o-rings on the return valve. There's nothing obviously wrong there (except that I can't put the metal cover on any more because I have replacement hose clamps that are too large), but from what everyone says, this is the #1 place to look, no?

Just try some bigger o-rings?
 
Top