Options for upgrading stock fuel pump lines/hat

When I went to prime the fuel system, it leaked at the connection between the fuel pump and the stock nylon lines.
Some members have swapped the nylon lines out for something else.

I tried this and broke the nipple/barb molded to the fuel pump hat.

Later I discovered an additional fault on the return line housing. This was probably created during the drilling process. I did not use a drill bit designed for plastic. They exist :)


Design rev 1

Use 1/4NPT to barb and clamp rubber hose to that.

I ran my rev 1 idea by some smart people with the idea of using a nylon fitting. It was suggested that I may want to allow for less stress/strain on the plastic of the fuel pump. This led to design rev 2.

Note: I eyeballed a tap against the FP hat. The plastic on the FP hat does not have anywhere near enough material to support a 1/4 NPT tap.

Design rev 2
Playing around in the garage, I noticed that there was enough material to drill out to 3/8".
Looking at the DF-supplied fitting that mates to the fuel filter, I realized metal SAE push-on 5/16" and 3/8" flared tube is this diameter.

What if we drilled out these FP hats to accept metal tube?

Materials


3/8" Fuel Injection Hose Clamps FI8

Dorman 800-082 Fuel Line Fitting
61A7Jj9PrlL._SL1500_.jpg

Dorman 800-155 Double Bead Fuel Line

Installed metal line



Fuel line assembly
Standard stuff, making hoses. I tried WD-40 and silicone (tire wet). Both worked rather well.

3/8" FI fittings work well. They are different from worm clamps.

Measure your lines before cutting. You may not want them the same length.

Routing & placement

The zip-ties aren't permanent ...or are they?
 
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terryjr

Well-Known Member
I was trying to look that unit up by the GM part number 15923596 and most of the units im seeing are steel. Maybe just get a different unit?

I don't know a lot about your system but they almost all run 43psi or more, mine actually gets up to 90psi. Just seems risky to me to glue fittings in.
 
You're right, it is definitely a lot of pressure. The system _should_ be around 4 bar ~60 PSI. With a boost referenced regulator I could see it getting up to 80 PSI.

I will be keeping an eye on the fittings. As it happened, they are a tight fit in the drilled holes. The sealant used is grey RTV. I'm no MechE and don't work with fluids, but these fittings would require quite a bit of force to pull out straight. Whether they are fuel tight ...we'll see. I suspect they are.

My current issue is a crack in the return line housing plastic. That is being sealed right now pending another test.

I definitely would prefer replacement sometime, it is just hard to find the perfect replacement at a good price.

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UPDATE:

Gel-type CA glue (I would have preferred super-thin with an activator and abrasion surface prep) seems to have sealed the leak. Will update if things change.

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UPDATE:

Things changed, the glue does not work. Now I will shop for replacements.

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UPDATE:

The Airtex E35099M fits and has the added bonus of a pressure sensor. It can be had for ~$50. Unknowns: Pressure & sending unit calibration.
TO BE CONTINUED :D
(This replacement fuel pump uses SAE push-on fittings.)
 
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