fuel flow drawing wanted, can't see how return gets in tank?

[Bart F-350]

Well, I don't really like to invent the wheel for a second time,hence my questions.
I got my rear tank full of fresh dieselfuel, and now know that they are (the both) 19 gal. or 72 Liter.
I undid the flexible hose from the steel lines to the pump, earlier on to see if the engine still ran, with a external fuelsource.
then I used a electric fuel pump to suck the fuel through the plastic lines until just before the lift pump, so that part is now full, and the gauge indicates a full tank. Check!

that only leaves me to find a way to connect my temporary fuel filter set up.
I found out that Ford uses a 3/8th? hard line from the lift pump to the filter head, the famous one with the "olives".
Why are this and the line from the filter to the feed from the IP hard lines? does that has to do with the 5 psi pressure that should be there?

If I can do that part with fuel hose for the time beeing, I can get my truck running, and tested and with that get my French CG (Carte Grise, something like your title I think), That took me only from 2005 when I bought her!

 

[chillman88]

You can safely run rubber fuel hose there to get it running.

 

[IDIBRONCO]

I found out that Ford uses a 3/8th? hard line from the lift pump to the filter head, the famous one with the "olives".

I'm pretty sure that it is a 3/8" line. There is only one olive on this line. It's at the top.

 

[Old Goat]

I replaced the Hard line from Lift pump to Filter head, you will need 2 Brass Barb 3/8" Fittings.

There is also a Delete from the Filter head to the IP.
https://russrepair.com/ Has the delete kit, look in the fuel system part of his site.

Need the metal fittings and Push lock hose, that is Diesel rated.

There is also the 3/8" curly Q hose going into the Lift Pump, that can be a problem when it get`s old and cracked.

Goat

 

[Bart F-350]

well, I have most things already in place, though with parts that I can obtain locally to avoid huge shipping bills.
I must say that you (in the USA) have nice parts special for this truck (obvious).

What I wonder, today I had tried to get her started, and with a electric fuel pump I had sucked the fuel from the tank right to the entry from the mechanical lift pump, then I had that hose , a fresh one, reinstalled, and I had the filter attached to the hardline coming from the lift pump and I tried to suck the fuel trough the filter, so that I'm sure that the whole circuit from the tank to the beginning of the hardline to the rear of the Injection pump was full of fuel.

The latter part (after the lift pump) to the hardline entering the Injection pump was very difficult to fill, I'm still not sure if it's full.
Is it possible to suck fuel through the mechanical lift pump?

I'm not sure of that, and with a combination of turning the engine over and using the electric pump I tried to get the engine running today, but I didn't succeed.
both my batteries are empty now and I'm recharging them now.

please if you think I made a mistake somewhere, correct me?

 

[chillman88]

The latter part (after the lift pump) to the hardline entering the Injection pump was very difficult to fill, I'm still not sure if it's full.

That's more fussing than you should have to worry about. It'll fill itself quick enough if your filter is full.

Is it possible to suck fuel through the mechanical lift pump?

It should be. The stock lift pump is basically just a check valve. I know you can push through it, (but you shouldn't, possibility to rupture the diaphragm).



Make sure you have the throttle fully open while cranking. It will move slightly more fuel that way.

Have you cracked the injectors loose? Usually crack them all loose and close as fuel bubbles out.

 

[Bart F-350]

Have you cracked the injectors loose? Usually crack them all loose and close as fuel bubbles out.

Didn't think of that!

 

[Bart F-350]

And I'm not sure if I made a small mistake?
I thought that I needed to connect the fuel return to the 2nd filter feed??? (have a look at the first image, the arrows at the filter head.)

That is because I'm not really sure what that should be doing?

 

[chillman88]

And I'm not sure if I made a small mistake?
I thought that I needed to connect the fuel return to the 2nd filter feed??? (have a look at the first image, the arrows at the filter head.)

That is because I'm not really sure what that should be doing?

The return port should not be on the feed side regardless. You're probably not pushing anything through the filter and it's just bypassing into the return.

That return line to the filter is only to bleed air out and can be safely disconnected.

If you do keep it move it to the outlet side and you need a restricted orifice inline or it will just bleed all the pressure out and starve the IP.

The 6.9 trucks had it between the filter and the IP. I don't know exactly how it was plumbed on those but it was kind of teed off right before the IP line at the filter.

If you have sucked all the air out of the system before the filter then plug that return line while you're trying to start it.

 

[Bart F-350]

Aha! That's why I emptied my batteries yesterday!

[If you have sucked all the air out of the system before the filter then plug that return line while you're trying to start it.]

and then reinstalling it when the engine runs?


Thanks.

 

[chillman88]

and then reinstalling it when the engine runs?

That's up to you. I have that line removed on both of my trucks and have no issues.

There are people who have had issues bleeding air out of the system because of deleting that return line. The only time I have ever had an issue I was able to bleed the air out using the Schrader valve on the filter head, and the only time that has happened was changing a fuel filter.

Might consider putting a shutoff valve on that line? That way it can be opened if needed to bleed air and closed the rest of the time. It at minimum should have a check valve in it.

The reason that line is commonly bypassed is because it can allow the system to "bleed down" and lose prime by allowing fuel to drain back to the tank. I can explain why in more detail if you need me to.

 

[chillman88]

If that's the original fitting you might be fine leaving the line in there as long as it's moved after the filter. It's supposed to be at the highest point in the fuel system. You're just trying to allow any air to escape the fuel system without passing a bunch of fuel through. Some of them had a check valve and it appears some of them did not. It really should have a check valve.

The way the system is designed to work is basically relying on vacuum.

If you were to fill your kitchen sink, then put a clear glass in it so it fills with water, then turn it upside down still full of water and lift it partway above the water level, the water will stay in the cup above the water level in the sink. As soon as you lift an edge of the cup above the water and let air in, you break the vacuum and the water drains out.

That's how the factory filter head works. It's full of fuel while running but when you shut it off you're relying on the return lines staying sealed. If there's any leaks in the return line system it breaks that vacuum on the fuel system and allows air into the filter, while the fuel back feeds through the pump back to the tank.

Bypassing that filter return line solves this issue. You could completely remove the fuel return lines and the fuel filter won't lose it's prime (but the injectors will sure make a mess hahaha).

 

[1mouse3]

That's up to you. I have that line removed on both of my trucks and have no issues.

There are people who have had issues bleeding air out of the system because of deleting that return line. The only time I have ever had an issue I was able to bleed the air out using the Schrader valve on the filter head, and the only time that has happened was changing a fuel filter.

Might consider putting a shutoff valve on that line? That way it can be opened if needed to bleed air and closed the rest of the time. It at minimum should have a check valve in it.

The reason that line is commonly bypassed is because it can allow the system to "bleed down" and lose prime by allowing fuel to drain back to the tank. I can explain why in more detail if you need me to.

You can put a primer pump on the frame tied into the feed line to aid in getting fuel back to the filter, I did that on a topkick with a cat to make filter change easy.

Add on Hand Primer Pump Check Valve for Diesel System replaces 0440011002 US | eBay

Perfect match for the original car. About Quality.

www.ebay.com

That is not the same quality one I found for it, it looked more like this being all metal but cant find one like it.

You must be registered for see images attach

 

[Bart F-350]

well, I find it harder and harder to keep myself motivated for this truck.
spent today again more time to start her, but no thank you.
At least I found out that that anti return thingie is one with the rubber flappers inside, and a 1/2" wrench turns the head.
oh, yes, the inside is not shutting off anymore.
so I blocked off the filter inlet where it was, and the return hose I put a 8mm bolt in with the spring clamp.
made sure the fuel arrived from the tank, and tried to start her.
dang, those battery cables really get warm!
tomorrow another day, maybe one of these day's I get lucky?

 

[chillman88]

well, I find it harder and harder to keep myself motivated for this truck.
spent today again more time to start her, but no thank you.
At least I found out that that anti return thingie is one with the rubber flappers inside, and a 1/2" wrench turns the head.
oh, yes, the inside is not shutting off anymore.
so I blocked off the filter inlet where it was, and the return hose I put a 8mm bolt in with the spring clamp.
made sure the fuel arrived from the tank, and tried to start her.
dang, those battery cables really get warm!
tomorrow another day, maybe one of these day's I get lucky?

I had a parts truck give me a real headache trying to get it running. After a few days fussing with it I finally got it to go.

Are you getting any fuel to the injectors yet?