Fuel strainer assembly loose from tank-928
#1
Fuel strainer assembly loose from tank-928
Anyone know a way to reattach fuel strainer assembly which has come loose from gas tank of 88 928? I hear it's common. I hate to have to buy another tank!
#2
Rennlist Member
You've got three threads going on this, I'll respond here because it has a sensible title
Welcome! Where are you located?
The strainer screws into a threaded metal insert which is molded in place when the tank is manufactured. It is not bonded, but the outer surface is knurled and gripped by the plastic tank. When the strainer and insert corrode then the insert spins when you try to remove it.
It is fixable.
One thread:
https://rennlist.com/forums/928-foru...r-problem.html
You can see the knurled OD of the insert stick on the strainer in post# 3.
One important thing to note: The strainer is sealed to the tank with a o-ring that fits a recess in the strainer. It doesn't seal to the insert, but directly to the tank. So it doesn't matter if there is a leak between insert and tank. (And there will be, because the metal insertis not bonded to the tank-- only held mechanically by the knurling.
Therein lies the fix: Get the insert off the strainer, clean it up (wire brush etc), stick it back in place the best you can, with a little JB weld or similar between the insert and tank- just to help out the knurled surfaces.
Be sure it is pushed in far enough so that it is slightly recessed, so that the strainer o-ring will seal against the plastic tank and not the insert.
Then-- and most important-- find a narrow hose clamp of the appropriate diameter to go around the strainer fitting. The tank has a "boss" that sticks out 3/8" or so, that you can get a narrow clamp around, to tighten the tank onto the insert. You will also need to shave off four small plastic bumps around that boss with a shark knife or wood chisel so that the clamp sits flat on the boss.
A picture in this thread, see post #8:
https://rennlist.com/forums/928-foru...er-or-not.html
I was able to easily do this without removing the tank. I am sorry that I didn't take any pictures.
It is also an excellent idea to add a clamp before removing the strainer.
An even better idea is to not mess with the strainer at all, but too late for that.
Welcome! Where are you located?
The strainer screws into a threaded metal insert which is molded in place when the tank is manufactured. It is not bonded, but the outer surface is knurled and gripped by the plastic tank. When the strainer and insert corrode then the insert spins when you try to remove it.
It is fixable.
One thread:
https://rennlist.com/forums/928-foru...r-problem.html
You can see the knurled OD of the insert stick on the strainer in post# 3.
One important thing to note: The strainer is sealed to the tank with a o-ring that fits a recess in the strainer. It doesn't seal to the insert, but directly to the tank. So it doesn't matter if there is a leak between insert and tank. (And there will be, because the metal insertis not bonded to the tank-- only held mechanically by the knurling.
Therein lies the fix: Get the insert off the strainer, clean it up (wire brush etc), stick it back in place the best you can, with a little JB weld or similar between the insert and tank- just to help out the knurled surfaces.
Be sure it is pushed in far enough so that it is slightly recessed, so that the strainer o-ring will seal against the plastic tank and not the insert.
Then-- and most important-- find a narrow hose clamp of the appropriate diameter to go around the strainer fitting. The tank has a "boss" that sticks out 3/8" or so, that you can get a narrow clamp around, to tighten the tank onto the insert. You will also need to shave off four small plastic bumps around that boss with a shark knife or wood chisel so that the clamp sits flat on the boss.
A picture in this thread, see post #8:
https://rennlist.com/forums/928-foru...er-or-not.html
I was able to easily do this without removing the tank. I am sorry that I didn't take any pictures.
It is also an excellent idea to add a clamp before removing the strainer.
An even better idea is to not mess with the strainer at all, but too late for that.
#3
Rennlist Member
I lied, I do have pictures.
Here's the knurled insert after I got it loose from the strainer fitting (internal pump in this case, it was our '90 GT).
Here's the "boss" in the molded tank where the insert goes. Note the four "bumps". The OD of that boss (without the bumps) is 47.0 mm.
Here's the bumps shaved off with a wood chisel and a knife. Don't nick the outer sealing surface.
The insert wants to go in from the inside, because the sealing surface has a small lip-- it will pull out, but it is very hard to push it back in. So I removed the tank-sender and sent the insert down that hole on a piece of wire as a guide.
Here is the special tool for pulling it in place, from the inside (made from 1/2" plastic electrical conduit IIRC):
I stuck a length of threaded rod through it, with washers and nuts on each end, to make a simple slide-hammer:
Here's the insert back in place. Looking at the pictures, I don't think I used any JB-weld-- just tried to get the knurling lined up as it was originally.
There were some irregularities in the knurling that could be matched between tank and insert. once close, it seemed to key into place nicely.
Here's the clamp from my spares box, I think the number reads "681210" but I can't find that anywhere:
And the clamp in place:
The clamp reinforces the plastic, and lets the knurling do its job. The o-ring seals against the surface that you can see, and as long as that is reasonably smooth then it will seal.
Use anti-seize on the strainer, and don't over-tighten.
Here's the knurled insert after I got it loose from the strainer fitting (internal pump in this case, it was our '90 GT).
Here's the "boss" in the molded tank where the insert goes. Note the four "bumps". The OD of that boss (without the bumps) is 47.0 mm.
Here's the bumps shaved off with a wood chisel and a knife. Don't nick the outer sealing surface.
The insert wants to go in from the inside, because the sealing surface has a small lip-- it will pull out, but it is very hard to push it back in. So I removed the tank-sender and sent the insert down that hole on a piece of wire as a guide.
Here is the special tool for pulling it in place, from the inside (made from 1/2" plastic electrical conduit IIRC):
I stuck a length of threaded rod through it, with washers and nuts on each end, to make a simple slide-hammer:
Here's the insert back in place. Looking at the pictures, I don't think I used any JB-weld-- just tried to get the knurling lined up as it was originally.
There were some irregularities in the knurling that could be matched between tank and insert. once close, it seemed to key into place nicely.
Here's the clamp from my spares box, I think the number reads "681210" but I can't find that anywhere:
And the clamp in place:
The clamp reinforces the plastic, and lets the knurling do its job. The o-ring seals against the surface that you can see, and as long as that is reasonably smooth then it will seal.
Use anti-seize on the strainer, and don't over-tighten.
Last edited by jcorenman; 08-29-2014 at 04:35 PM. Reason: added captions
#4
Team Owner
#5
Rennlist Member
I had the same issue on my 79. Used J B weld and inserted it from the front side with a slight amount of trimming to the lip of the tank. Tank was removed.
I ensured the insert and tank lip were flush to allow the strainer seal to make good contact.
Been three years and had the strainer out a few weeks ago with no evidence of issues. Still holding and still leak free.
I ensured the insert and tank lip were flush to allow the strainer seal to make good contact.
Been three years and had the strainer out a few weeks ago with no evidence of issues. Still holding and still leak free.
#6
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I have recently replaced a tank, no issues with the outlet, (self inflicted split-with the aid of a floor jack)
Neither the old tank or it's replacement had a hose clip around the outlet (or any evidence of one being there) are you sure this is not a previous owners attempt to put a bit more pressure around a leaking insert?
Neither the old tank or it's replacement had a hose clip around the outlet (or any evidence of one being there) are you sure this is not a previous owners attempt to put a bit more pressure around a leaking insert?