Alternate CAT fuel filter T holder

I have seen various versions of this over the past year. Most involved cutting a piece of metal, drilling it, and install. I figured there must be an easier way. There is.

As you may have noticed, when using the old style thermostatic T retainer, there is a small gap between the bottom of the T and the filter head. In a few cases, the O rings do not fully seat when using the supplied retainer. With this modification to the CAT fuel filter, you have the thermostatic T sitting flush on the filter head, and the O rings fully inserted into the hole.

Note: This mod is for the earlier generation CAT fuel filter heads. If you have one of the later generation filter heads, the screw holes are spaced wider apart. This mod will not work with the braces listed below. You will recognize the newer heads if the thermostatic T holder has a circular opening that the top of the T fits into.

You will need the following parts:

#8x32x1.25 inches machine screws $0.10 each
#8 or #10 x .75 inch nylon spacer $0.30 each
#8 star lock washer $0.10 each
2"x1/2" mending braces $2.99 for a package of 4



I obtained all these parts at a local hardware store for the price listed. If you want galvanized braces instead of brass-plated, you can save 50 cents.

The mending braces have two holes drilled in them. Guess what? Yup, perfectly spaced for the CAT filter head screw holes.

The purpose of the nylon spacers are to protect the thermostatic T. You won't have a screw thread damage the T by using these.

Take your brace, and insert one screw/star washer through each hole. Add your nylon spacer to the protruding shaft of the screw. Place over the top of the thermostatic T, and secure evenly. If you want the spacer to stay in place, put a bit of silicone glue in the hole before inserting the screw. Wipe excess silicone off the protruding screw threads. You won't ever lose parts this way.

The next two pictures are self-explanatory.






This may be the cheapest mod I have ever done. Hope this helps someone else who has been contemplating something similar, and did not want to make a custom piece.

Bruce

UPDATE: I have replaced the regular screws with allen head cap screws in the same size listed above. The Phillips head screws were starting to strip out. It looks cleaner, too.

Now thats damn smart!!! Wooohooo. Simple is effective. Greg, I think its time to make revision 3. It would be very solid, and probably less expensive to manufacture.

Nice work Bruce! Great adaptation. Thanks for the parts list. This one is going in the queue.

cosmic said:

Nice work Bruce! Great adaptation. Thanks for the parts list. This one is going in the queue.

Click to expand...

Don't buy a plate. I have two spares, after I do the Golf. You know where I am!

Justin, Greg addressed the slight elevation of the T with his new T holder. If anyone wants to modify their old T holder, just hog out the opening where the T sits until it is wider than the T base. Then bend the top down to make the T sit flush.

paramedick said:

Don't buy a plate. I have two spares, after I do the Golf. You know where I am!

Justin, Greg addressed the slight elevation of the T with his new T holder. If anyone wants to modify their old T holder, just hog out the opening where the T sits until it is wider than the T base. Then bend the top down to make the T sit flush.

Click to expand...

Yeah, I tried that, but it still wasnt enough. If there is any pressure from the hoses, it can still lift or twist the T enough to let in air. I've since done the metal plate mod, but left out the nylon spacers. Its working great.

a mod for a mod. i luv it. nice work!

I have got to thank you for this. I had to remove my CAT filter setup a while back as it was sucking air and causing intermittant start up problem. I came across this thread last week, reinstalled the CAT this weekend and no more air bubbles. Woot!!

Thanks for the parts list Bruce.

paramedick said:

This may be the cheapest mod I have ever done. Hope this helps someone else who has been contemplating something similar, and did not want to make a custom piece.

Bruce

Click to expand...

Humm, you haven't done any Ventectomy's?
That's my cheapest mod to date.

I don't count the ventectomy as a mod. I just look at it as correcting a factory VW mistake!

Here's Steph's filter mod from Gmarks GTG on April 22, 2006.

Didn't get to take you up on your plate offer, but at about $5 for the whole mod, no worries! Got this in the other weekend. I will snap a pic sometime soon.

paramedick said:

Don't buy a plate. I have two spares, after I do the Golf. You know where I am!

Click to expand...

Hi Bruce, I went out an purchased the parts but it turns out a 2" mending brace was too short. The screw holes on my CAT filter head appear to be slightly further apart than 2". I even held the CAT-kit T mount bracket up to the 2" mending brace and found the screw slots on the bracket were slightly further apart than the mending brace was long. I just bought my CAT conversion kit a month or two ago. I wonder if the screw holes have been recently relocated? -rod

They have indeed been relocated on the newest version of the CAT filter. This only works on the older/original models. Sorry.

If you're having an issue, talk to Greg. He swears that the new design T holder is perfect.

Thought i would bring this to the top. This seems like a great idea for those having trouble with the original design. I don't see why it would not work on the new design as well.

Well, since I just went through this with the newer style clamp, I thought I'd share what worked for me. The new clamp wasn't holding the T firmly in place and it leaked. I tried bending the clamp to put more pressure on the T but it ended up only putting more pressure on one side of the T and it still leaked. Frustrated, I PM'd Paramedick and he referred me to this thread.

The mending brace needed for the new style filter head is 2 1/2" x 5/8". I however could not find one at my local hardware store so instead I purchased a "corner brace inside L" with the same dimensions. I ended up having to cut the L at the 90 degree angle to give me 2 equal pieces. I now have a second piece for when I install a Cat filter kit on my 05 Passat.

All of the other bits & pieces that Paramedick mentioned in the earlier post are the same and will work with the newer style filter head.

I used a 2.5" L-brace as suggested, but the hole spacing was off for me. It was necessary to drill another hole for the second #8 machine screw. First I straightened the L-brace with a hammer so it looked like this:
________
| o o . o o |
Then I broke it about 60% down it's length with a vice grip and a big pair of flat-nosed pliers so it looked like this:
_____
| o o . . |
Finally, I drilled a 3/16" hole so it lined up with the second hole on the filter head:
_____
| o o . o |
Thanks for the tip. I had a SEVERELY hard start this morning after installing my CAT filter. I clamped the hoses and popped off the T-fitting to find the fuel level way down. I'm pretty sure it was the T-fitting, so we'll see how it goes. This mod certainly got the T-fitting tight.

Keep in mind, on non-pd cars, hard starts can sometimes be attributed to leaking injection pump seals. I've seen pump head seals that dont leak fuel out, but when the engine is shut off, will allow air to be sucked in. This causes a no-start or hard start similar to the symptoms of a leaky thermo-t.

I want to eliminate the "T" and just plug the hole in the top of the filter housing so I can just send the return line all the way to the tank, bypassing the filter altogether. Is there a post which shows you how to do this?

Found my answer in this thread below

http://forums.tdiclub.com/showthread.php?t=290984