FredR

Tank failure at this position is a real problem that needs a solution as every tank will likely experience this sooner or later and replacement, although still available [for how much longer??] is an expensive proposition. If the OP can come up with a viable solution for all failure modes that would be a great addition to our needs.

The limited [4 No] failures I have seen all involved failure of the plastic boss that holds the steel mount. This is what I term the "underlying failure". The root cause of the failure was not quite so obvious but most likely involved degradation of the parent material due to age hardening of some kind possibly coupled with overstressing during either removal or insertion of the in tank pump [or strainer].

Until recently I had a spare tank from my late S4 that failed and I took a long look as to how I might be able to fix it should I experience failure of my currently fitted tank. The boss had failed having radial cracks at two locations and I concluded that the only way a fix could be made was to have a new insert along the lines shown but with a threaded outer surface upon which a securing ring could be used to tighten the fitting and thus compress a seal ring at the base of the new unit after first removing the original boss altogether.

At the moment I am not sure how this new mod actually works sealing wise [a query Dave asked in an earlier post] - I presume it is a "push fit" of some kind that holds the insert in position. If so this would leave me wondering whether such can work on a boss that has cracked in the manner I describe above.

Whatever mechanism it uses to maintain sealing integrity, if experience proves this mod works long term it will be a much needed and appreciated innovation.

dr bob

Fred --

This insert, like the original, depends on the integrity of the flange at the end of the molded nozzle section of the tank. All the sealing is done by the ring gasket, pinched between the end of the sleeve on the inside and the supported flange on the tank, and the mushroom part of the outer fitting with the shallow groove in it. Your example with radial cracks in that area would not benefit from this piece, unfortunately.

For those who have suffered a spinning insert while trying to remove the original fitting, you'll still have to get the factory insert out without damaging the molded flange section of the tank. That means no prying with screwdrivers that might dent or nick the tank plastic there. Jim Corenman's previous recommendation for using a slide hammer to remove the whole assembly is an excellent option if you can get the old ring gasket out first. Even then, the tank nozzle flange will be stretched/expanded as the old sleeve is extracted. Ideally, one would be able to Dremel the whole outer section or at least the large mushroom head off the old fitting, leaving nothing bigger than the threaded part. Then the insert could be pushed back into the tank and extracted via the sender hole.

There's enough discussion available just on removing the fitting and sleeve to deserve a separate thread.

FredR

Bob,

When the insert spins it shears the "nodules" that fill those little holes in the insert presumably made during the injection moulding process [the insert is not driven in after moulding or so I understand] - my concern being that after that happens there will be less resistance to shear for the insert. It seems there are two scenarios when the problem becomes apparent- either the thing suddenly develops a leak [for no obviously apparent reason at the time] or it spins when trying to remove the in-tank pump. The concept of fitting an external clamp is intended to increase the grip on the insert that may otherwise have degraded with time presumably a characteristic of the tank material and this will remain the same for the repair phase.

Thus your note that this type of mod will not work for the case I highlighted is pretty much a given - As to how well it will work longer term remains to be seen - hopefully experience will prove it to be a sound methodology.

The new design presumably pushes in from inside the tank and thus why I am struggling to understand how it seals unless the in tank pump flange pushes against the tank nozzle with a seal in the sandwich. I feel as though I am missing something that I should understand- but seemingly do not.

hacker-pschorr

It seals the same as the stock tank insert.

The outside flange has a rubber gasket which seals to the outside of the tank. As long as the insert doesn't pull out or spin, you can tighten up the insert to seal the assembly.

The insert has no sealing effect itself. It's just there to allow the insert to pull tightly against the outside of the tank.

polecat702

Guys, It's a bulkhead fitting. When it's assembled it draws everything tight by sandwiching the strainer or internal pump flange, with the insert inside the tank. The factory insert does not have a flange or anything supporting the insert from inside the tank. It's just held in place thru the molding process.

This is an ingenious solution to an expensive problem.

This thread came about at an opportune time! Had the insert spun in my tank, while replacing the internal pump, I'd be wanting this solution ASAP!

FWIW, I'm going to buy one as soon as it's available, something to have on hand just in case! This repair will out last us.

BauerR

You guys are exactly right! It seals exactly the same as the original style. However, the one major difference is, it wont ever pull through.

It works perfectly. As long as the outside lip on your tank is without issue, it will seal just fine.

Landseer

Fantastic solution to a really perplexing problem. Thank you.

BC

Let us know availability. Having one or more in stock could save a weekend tank job from being much more serious!

BauerR

I will definitely keep everyone posted.

I guess it wouldn't be a bad idea to get a rough count on how many people may want one. I imagine that they will probably be in the $100-150 cost range depending on how many I make

SB928

Trying to get our '79 RoW going and decided to address a small leak the last time it was running. I don't know if there was simple corrosion or the previous owner used some "glue"
but that filter sock fitting may as well have been welded to the tank sleeve seeing how it had to come out. Is the black gasket the original?
Here's the carnage:

Bigfoot928

using this new product would it be an additional benefit to use a hose clamp on the outside where the fitting clamps to add an additional surface to seal? I don't have one to test or access now.

jcorenman

Picture of the tank boss where it came out ??

SB928

I have a feeling that this tank saw a previous leak repair.

dr bob

That looks exactly like the tank outlet nozzle after the threaded insert has pulled out. No evidence of any prior repair that I can see.

The crosshatch showing in the nozzle matches the crosshatch on the outside of the threaded insert that was there previously. The yellowing plastic is the splash shield that sits in the bottom of the tank to maintain the level in the well there where the in-tank pump or strainer (and the bottom of the level sender) normally sit.

Inspect the outside lip to make sure there are no tears, and no damage that might affect the seal from the washer/ring gasket used with the thread-in hose fitting. If that stuff looks good, you are a candidate for BauerR's insert as a fix.

SB928

dr bob, I saw your thread about putting the sleeve back using 3/8" all thread rod and will probably use that method when I figure what to put back in. Hopefully BauerR's fitting will be available or I might have to find another tank to use and repair this one in the future.

Question is: How did you start your fitting and all thread rod/nuts down in the tank? I'm not the biggest guy, but even my hand doesn't fitting down the top of the tank.

I saw the thread that sort of led up to, I'm guessing, BauerR making this fitting and noted some good concerns from other members about the liability of making such a part that could some substantial damage. Maybe he should consider having buyers sign a liability waiver. Sad we live in such a litigious world, but understandable. I'd like to think that it would be up to me to decide if this is the route I wanted to pursue in fixing this issue. Are my skills/knowledge/tools up to the task and would I be willing to live with the acceptable risks? I guess it boils down to most things in life, and that is, how much attention are you going to pay to something that needs your attention? Put this fitting in half-baked, let it leak in your garage, ignore the obvious gas smell, and well......get all blowed up.
Sometimes you need to listen to that little voice in your head that says, "man, I would do that sh_t if I was you" (Chris Rock) but if you're capable, AND willing to monitor the situation, I feel this is an acceptable solution to the issue.
Thanks
Bob