Fuel Fitting on Mechanical Pump

pj31704

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I wanted to see what others have used to run your fuel line from the mechanical pump up to the filter then to carb. I have replaced the pump before and was never happy with the previous owners setup. Since I need to replace it again I figured I would take the chance to fix this.

The current setup has an old steel line that screws into the pump, it looks like at one time it ran the full length to carb, but basically has been cut after about 8" and has a fuel line attached. This then runs to my filter and to the carb. I would like to run the steel mesh line this entire length, but my hangup is how to attach it to the pump where it needs to be screwed in. I have found a few 90 degree fittings, however I am unsure if I would be able to use since they do not have the same free moving thread. And I think if I tried to ***** on the fitting the line that comes out on the 90 degree bend would hit the line going into the pump.

Hopefully this all makes sense, if anyone has images of their setup from the pump or products they have used I would appreciate it.
 

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goodO1boydws

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The closeup of the steel line fitting looks as though it's most likely the same thread and size as those used on brake lines. And it looks as though that steel line is either 5/16" or 1/4" or the metric equivalent. (On older vehicles brake lines are much bigger diameter than on the newer cars.)

Take the metal line to an auto parts store and see if it matches a fitting that they have which is already ON a brake line. Then just bend the line to whatever configuration you need and cut it wherever you want.

The OEM steel lines are always hard line tubing, because they need to have have a lot of bends to stay clear of everything-for safety.
To use that type of tubing, and to make anything but a very shallow or large radius bend, a small diameter tubing bender is used to keep the line at maximum flow capacity. Without one the line flattens if you put sharp/small radius bends in it.
(Inexpensive tubing benders are readily available and useful for keeping the line looking "professional"/neatly routed, and handy for keeping brake lines tucked if you ever need to splice or duplicate a brake line.)

You MAY be able to get by with using the hand-bendable tubing if you only run a short length, and lots of people do, but I don't recommend that for this situation on a vehicle that may go off road and bounce around much. Any wrench slip or other force pulling or pushing on it can much more easily deform a soft line that is already in place.
Like a long length of steel covered flex line flopping around. (relatively heavy-compared to plain hose)

If this was mine, and if I was determined to use it, I'd run the hard line at least far enough to where a transition to the steel mesh covered line isn't obvious.
 

johnnyreb

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Also you might want to check where it screws into the fuel pump. It looks bent to me and I have never seen one bent their. They are straight.
 

goodO1boydws

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jonnyreb's right about that bend looking suspicious.

Now that I look at it more closely, I can also see that the first bend on the line definitely has a small kink. I've seen as close, 90 degree bends in steel lines before, but the factory ones are never kinked (when first installed), as they have the proper line forming tools.

The steel line looks to have enough surface rust and is dirty enough to be the original-and the fitting has surface rust too, plus it looks to have been on and off a few times with an ill-fitting or wrong size wrench. Even if its not original its been there a LONG time.
If the line IS the OEM hard steel type its very possible that at one time someone ahead of you (or you) may have accidentally bent that line more than it HAD been. Which is consistent with cutting that line and then running a piece of rubber hose up to the top fitting.
Or it may be a replacement one that's "owner-made" (a long time ago) and if so, it would be more likely to have had that kink from the start.

By the way, how about looking closely at the top fitting-the carb end?
It would obviously terminate differently from the lower one if it HAD been designed for rubber hose attachment. The original types and most if not all aftermarket ones designed for use with a hose have a swelling to help retain the hose. If a steel line had originally been attached there it would likely have used a captive nut like the lower one. If the top fitting ends with no swelling of any kind, the tip of the fitting has been cut off.
For that matter the top end of the existing line where the hose attaches to it should have a swelling too if its original.
 
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johnnyreb

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If you were close buy I,d give you a pump. If its a AIR TECH---LOOK OUT. They are nothing but troubles and junk,. Throw it in the trash or get your money back and get a Carter or anything but AIR--TECH.
 

johnnyreb

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I wanted to see what others have used to run your fuel line from the mechanical pump up to the filter then to carb. I have replaced the pump before and was never happy with the previous owners setup. Since I need to replace it again I figured I would take the chance to fix this.

The current setup has an old steel line that screws into the pump, it looks like at one time it ran the full length to carb, but basically has been cut after about 8" and has a fuel line attached. This then runs to my filter and to the carb. I would like to run the steel mesh line this entire length, but my hangup is how to attach it to the pump where it needs to be screwed in. I have found a few 90 degree fittings, however I am unsure if I would be able to use since they do not have the same free moving thread. And I think if I tried to ***** on the fitting the line that comes out on the 90 degree bend would hit the line going into the pump.

Hopefully this all makes sense, if anyone has images of their setup from the pump or products they have used I would appreciate it.
I ran into the same thing. They had 2 0r 3 different size lines. I took it all off and ran one size.
 

goodO1boydws

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With that bent fitting on the pump you're surely going to return it, right?
Once you thread something onto it or let gas in they can refuse to take it back.

I just looked up your vehicle at rockauto, and in the Carter's description, it looks as if the 302 in a Bronco 1969 through 1974 used the lower of 2 pressure output fuel pumps, the M6588. That one has a 5.5-6.5psi rating, with a 5/16" pump inlet diameter. For even a moderately modified 302, that pump should be more than sufficient.

If you're running a STROKED 302, with a bigger carb or multiple carbs and/or cam, and/or you tend to run at high rpm, you might want to look at one with a higher rated output. Or just run an electric and save the hp drain.

In that case, Carter also has the M6962.
This pump is rated at 6.5-8.0psi
(For reference, they're both under $20 at rockauto.)
The main external difference being that the M6962 pump's inlet is 3/8", so a larger diameter rubber hose should probably be used to ensure that the 5/16" hose doesn't split at the fitting.
 

chrlsful

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it all looks pretty suspicious to me. But I have the i6 (upraded to 4.1).

Anyway, a lill late for the thread. Mine I run the pump 'wrong side up' from this one, I don't use brake line, but metal all the way to carb (reduce fire hazard) and looks like this:
https://www.vintageinlines.com/customer-cars?pgid=kg1lf2p0-4d31f578-d6ef-4a09-bf0f-3a283a6a4eb8

see already made up 5/16 line for bronk 302 '69/77:
 

goodO1boydws

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it all looks pretty suspicious to me. But I have the i6 (upraded to 4.1).

Anyway, a lill late for the thread. Mine I run the pump 'wrong side up' from this one, I don't use brake line, but metal all the way to carb (reduce fire hazard) and looks like this:
https://www.vintageinlines.com/customer-cars?pgid=kg1lf2p0-4d31f578-d6ef-4a09-bf0f-3a283a6a4eb8

see already made up 5/16 line for bronk 302 '69/77:
That looks like a very good source for Bronco stuff-ready to install steel fuel and brake lines. I'm envious of the preformed stainless steel brake lines.
 
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Motech

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A section of thinner and softer copper tubing works great for mocking up the shape you will need to bend yourself a new line. In a pinch, a steel wire coat hanger works too, quite well in fact if you slide some fuel or large vacuum hose over the length.

Once you have that length all squared away, hopefully you can find some pre-flared steel line very close in length with fittings already installed so all you have to do is bend it, no cutting or flaring necessary.
 

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