1972 ENDT-675 Fuel Lines

[tenfive0]

I had to take the radiator out of my CF-600 for repairs. While the truck is apart, I am cleaning up the best I can 48 years’ worth of neglect, dirt and grim. I used degreaser and a pressure washer. There was no avoiding using a pressure washer. In some areas under the truck and in the engine compartment the built-up grease and filth was caked on nearly 3/8" thick. I tried my best to avoid nicking any fuel or oil lines, BUT. 

The radiator popped the core as the result of a blown heater hose. I suspect the heater hose was original factory installed. The core was living on borrowed time and was weeping slightly (not leaking) before the heater hose blew. Last year the truck blew an oil line that I caught right away before the truck went up in flames or caused any engine damage. These two experiences and a few other minor incidences have convinced me I need to replace all the hoses, belts, fuel and oil lines to avert further disaster.

I’ve owned the truck for 2-1/2 years, and it’s been a work in progress. I’ve attached pictures. I need to replace these fuel lines shown. I'm guessing these are low pressure lines. When I remove and replace them will I have to do any type of a procedure (crack open an injector or two or three) to bleed the fuel system of air to start the engine.

 

[terry]

On that item that you labeled what is this, it is what your needing a fuel primer. unscrew that wingnut and tip that to one side and pump the handle up and down to prime the fuel system, might take quite a few strokes but it will prime it up.    terry

[Maddog13407]

he forgot...… it will probably take 100 pumps but it will prime

[41chevy]

Or more if the seals gone awol... don't ask how I know.

[tenfive0]

I have a small Skid Steer that had a bad fuel cap that was not venting correctly. As a result the fuel system drew a vacuum and the plastic fuel tank collapsed (puckered) inward on itself. When to tank collapsed the fuel sending until float got stuck in the pucker/squeeze and stopped working. Took a while to figure out WTF. I ran the Skid Steer empty a few times. The fuel gauge always reading 1/2 full. Put fuel in the tank and it only took (5 Gallons) half the amount to fill the 10 gallon tank. WTF?? Finally (dumb ass) took a flash light and looking in the tank. WTF? The Skid Steer tank fix was - I took the old cap and put a tire valve stem in it. I put the cap with the valve on the tank, pressurized the tank and blew it up back in to shape. Got a new cap that was venting correctly and it has been good for the past year or so, knock on wood. 

When the Skid Steer ran empty I'd squeeze a fuel line primer bulb until I felt resistance. If the engine wouldn't start I'd squeeze some more. When the engine would finally start and it sounded like it was going to stall I'd squeeze some more until the engine ran smooooooth. I'm guessing the "WHAT IS THIS" in my original posted pictures is the same theory. Pump until I feel resistance try to start the engine and then pump some more. 

I won't ask - How many licks does it take to get to the center of a Tootsie Pop. Because sure as shi_ if anything can go wrong it will be more difficult then expected. NOTHING THE EASY WAY. Will I need to leave a few of the new lines bottom to top loose and have at it and pump away and then tighten loose fitting bottom to top as I see fuel?  Or, do I tightened everything up and pump my nuts off until I feel resistance? I might try the fuel cap trick and gently pressurized the tank with a few pounds of air with some new line fittings loose until I see fuel. Then tighten the fittings and pump. Can I pump while the engine is trying to start or while it running? I don't want to damage anything because the budget is getting thin. I assume there is no lift pump on my truck? The first fuel filter on my truck is located next to the fuel tank behind the rear axle. I have never found the easy button. What a nightmare. I have a remote oil filter canister with oil lines running to the engine. Last year on of those lines took a dump. I like my Mack but what were they thinking with the miles of ALL the oil, fuel, power steering and coolant lines?

 

 

[Rob]

I'm seemingly fond of starved out diesels in the driveway around here so I built up a little manual pump. After dumping some diesel fuel into the tank, I attach this pump to the inlet side of the primary fuel filter after removing the fuel discharge line of the transfer pump, give a few strokes till I hear fuel slosh or return to the tank, and fire up the engine. When the disconnected line of the transfer pump begins spewing fuel, I shut down the engine, disconnect my temporary pump, reconnect normal, and all's good till the next starve out on the same truck as I never learn.

You can do the same with a cheap electric chinese pump off of ebay, but you'll need one that will output better than 15psi to get past the check/flow valve that keeps the fuel gallery in the injector pump pressurized. A homebuilt accumulator system charged to 20psi with air will work well and can be fashioned from an old small air compressor tank easily.

This is not really a cheap pump but would do the trick:  https://www.ebay.com/itm/JEGS-159000-Hi-Pressure-Inline-Fuel-Pump/312936286755?epid=21012717744&hash=item48dc74ca23:g:uYkAAOSwZgheFurH

My manual pump/accumulator set will go in excess of 50psi and holds about 2 quarts of fuel.

Edited March 12, 2020 by Rob

[tenfive0]

Adding to my confusion. HELP - What is this mark (B) in the attached pictures.

[6368]

air compressor

 

[Freightrain]

I've also had to pump my primer a time or three.  If the valve is good, it will pump up quickly and you will feel resistance and feel the fuel as it bleeds back to the tank and that will be enough for it to fire.  No bleeding of any lines.  The primer on my 237 was nonworking when I got the motor.  Unbolt the transfer pump, remove it, then carefully unscrew the primer.  Just a one way check valve, nothing to it.  Mine just needed unstuck and now works fine.

If the truck runs now, try pumping the primer.  If there is resistance, it is fine.  It doesn't take that many pumps to get fuel up from a tank.  20? 30?  Not 100.

When I bought my truck, it didn't go anywhere far until I replaced ALL the lines(fuel and water).  You can buy the line and reuse most fittings( if they are the type).  

The compressor has coolant running through it, thus those two lines.  The rear one might be a pita to reach without removing the pump.  Depends on your wrench selection. 

Edited March 14, 2020 by Freightrain

[tenfive0]

11 hours ago, 6368 said:

air compressor

 

I should have known that. I guess I was blinded by science.

 

10 hours ago, Freightrain said:

I've also had to pump my primer a time or three.  If the valve is good, it will pump up quickly and you will feel resistance and feel the fuel as it bleeds back to the tank and that will be enough for it to fire.  No bleeding of any lines.  The primer on my 237 was nonworking when I got the motor.  Unbolt the transfer pump, remove it, then carefully unscrew the primer.  Just a one way check valve, nothing to it.  Mine just needed unstuck and now works fine.

If the truck runs now, try pumping the primer.  If there is resistance, it is fine.  It doesn't take that many pumps to get fuel up from a tank.  20? 30?  Not 100.

When I bought my truck, it didn't go anywhere far until I replaced ALL the lines(fuel and water).  You can buy the line and reuse most fittings( if they are the type).  

The compressor has coolant running through it, thus those two lines.  The rear one might be a pita to reach without removing the pump.  Depends on your wrench selection. 

The coolant lines to the compressor threw me off a bit but it make sense now that I think about it and know for sure what I'm looking at.

[tenfive0]

The truck is or was currently running before I had to take the radiator OUT for repairs. I haven't as of yet taken any of the fuel lines off. One disaster at a time. I'm going to wait until I get the radiator back in the truck with all its parts and then start the engine to test for coolant leaks. I plan to drive the truck around slightly for a while to assure the radiator fix is holding. Then I'll address the fuel lines. 

I gave the primer a few pumps this morning. It leaked or seeped a little fuel down where the plunger meets the body.  After a few pumps the leaking appeared to lessened or stop. I didn't want to mess with it to much so not to screw anything up. It felt like the primer was giving some slight resistance but I don't know what is normal or what to expect. I guess its okay? 

[Rob]

Make you up a little pump like this and the task of priming is easy:

A manual transfer pump like you would use in a pickup bed, some fittings, and hose is all you need.

This one has worked for me probably a hundred times so far.

[tenfive0]

On 3/13/2020 at 8:25 PM, Freightrain said:

I've also had to pump my primer a time or three.  If the valve is good, it will pump up quickly and you will feel resistance and feel the fuel as it bleeds back to the tank and that will be enough for it to fire.  No bleeding of any lines.  The primer on my 237 was nonworking when I got the motor.  Unbolt the transfer pump, remove it, then carefully unscrew the primer.  Just a one way check valve, nothing to it.  Mine just needed unstuck and now works fine.

If the truck runs now, try pumping the primer.  If there is resistance, it is fine.  It doesn't take that many pumps to get fuel up from a tank.  20? 30?  Not 100.

When I bought my truck, it didn't go anywhere far until I replaced ALL the lines(fuel and water).  You can buy the line and reuse most fittings( if they are the type).  

The compressor has coolant running through it, thus those two lines.  The rear one might be a pita to reach without removing the pump.  Depends on your wrench selection. 

Before I'm doomed to exile I want to thank everyone for their assistance in this tread.

I have not tackled the fuel lines yet. I want to get the radiator and coolant line issues resolved first and get the truck running before addressing the fuel lines.

Yesterday day while socially distancing from humans I hung out with the old lady and dogs. I choose to show my truck some love. I took off the coolant line from the compressor to the block. I wasn't to much of a PITA. I took the top of the hose off the block fitting. I spun (loosened) the fitting on the compressor with the hose attached to the position shown and then I took the hose off the compressor.