FD Seam Leaking?

[Funracer]

Checked and tightened all the fittings. Looks like a seam leak but if so it’s happening all the way around. Where else could it be coming from?

Thanks

[jess p]

Are you certain it’s leaking at the seam and not dripping from one of the fittings above. If it’s leaking at the seam I’ve seen members carefully disassemble the FD at the seam and brush a thin film of copper sealant on each half and reassemble with no leaks.

[Funracer]

Originally Posted by jess p

Are you certain it’s leaking at the seam and not dripping from one of the fittings above. If it’s leaking at the seam I’ve seen members carefully disassemble the FD at the seam and brush a thin film of copper sealant on each half and reassemble with no leaks.

I assumed it was something above leaking down and catching the seam then running around. Tightened all four on the front side today. Lots of mirror inspection and no obvious leak from any fitting.

So you know of Fuel Distributors that leaked like this and were repaired with copper sealant? I will do a search but I have read easily dozens of FD threads and never read of one leaking from the body like this.

Thanks

[boyt911sc]

Originally Posted by Funracer

I assumed it was something above leaking down and catching the seam then running around. Tightened all four on the front side today. Lots of mirror inspection and no obvious leak from any fitting.

So you know of Fuel Distributors that leaked like this and were repaired with copper sealant? I will do a search but I have read easily dozens of FD threads and never read of one leaking from the body like this.

Thanks

Neil,

This is a common failure with the fuel distributor. The leak is between the steel diaphragm and the lower or upper section. Once the seal or bond is compromised, tightening the bolts will not fix the problem.

Unfortunately, a complete disassembly and re-assembly would be needed to fix the problem. Check with your rebuilder for warranty. How many years since it was rebuilt? This is not a rebuilder’s fault. It does happen even after a year or two from rebuild date.

If your rebuilder will not fix it, send it to someone who could fix it. With all your recent problems, you need a break. You still have my address?

Tony

[Funracer]

Thanks Tony. My car is starting perfectly every morning. So nice. And now this. It was rebuilt in 2020 so surely out of warranty.

I will recheck all the fittings. If that does not do it might take a shot at it myself. At this point why not?

Regards

[E Sully]

If uou want to try yourself.
https://www.ebay.com/sch/i.html?_from=R40&_nkw=bosch+porsche+fuel+distributor+kit&_sacat=0&LH_TitleDesc=0&selcontext=productType%3ACAR_AND_TRUCK&selvel=Submodel%3ASC%2CYear%3A1983%2CTrim%3ASC%2BC oupe%2B2-Door%2CModel%3A911%2CEngine+-+Liter_Display%3A3.0L%2CMake%3APorsche%2CEngine%3A 3.0L%2B2999CC%2BH6%2BGAS%2BSOHC%2BNaturally%2BAspi rated&rt=nc&LH_ItemCondition=3

[Funracer]

Yes I have a Salvox kit in my eBay cart. But my FD was just rebuilt in 2020 and probably doesn’t have 1000 miles on it. Can I just open both halves, clean and reseal with Loctite 574?

This from the Salvox website:

[E Sully]

The choice of using a sealant is up to you. I believe John Walker used a very light film. I skipped it myself. My steel plate has a very small pinhole that must remain clear.
When I rebuilt the top end on my '86 I used a very thin coat of 574, and their was a small amount of squeeze out when I put the cam tower on. I'm not sure the fuel would wash it out cleanly. I would want to avoid that due to the small slits and passages.
Here's a good thread with some differing opinions.
http://forums.pelicanparts.com/porsche-911-technical-forum/272657-cis-fuel-distributer-cleanout-w-pics.html

[eastbay]

Try tightening the 3 screws, seen it work before.

[Funracer]

Originally Posted by eastbay

Try tightening the 3 screws, seen it work before.

I did that and it seemed to help a bit. This lead me to think tightening the screws on the back might stop the leak altogether. Thanks

[Funracer]

Was planning to reseal the top and bottom with Loctite 574. Ordered it on the 12th and still not here. Got tired of waiting and had spare time so I did the following…

Pulled the FD again no fun in a hot garage. Note the screw yellow paint marks:


Got lucky and found a T27 bit in my box. My guess is the screws are T27 or T28. Nothing else came close to working. Anyway was able to turn each screw just a tad:


Compare these paint marks to the same ones above. Moved just a bit.


Reinstalled and did a fuel pump only pressure test followed by a good 40 minute drive. Dry as a bone:


Still no Loctite. Now I don’t need it

[E Sully]

To follow up on this, I used cis-jetronic rebuild kits.
In regard to the cast iron fuel distributors the recommend 10-15Nm, which is about 10 ft/lb of torque when tightening the screws on my fuel distributor.