Fuel pump return and feed line

[coreydmc]

I noticed a puddle of fuel under the front of my car. I removed the fuel pump inspection cover in the trunk and noticed the return and feed lines are cracked and deteriorated. Can I just replace them with rubber fuel hose from NAPA? My lines now have a threaded one way insert into the hose end that connect to the metal tubing. I was wondering if I can just use a hose clamp for the new hose. Also there is a banjo one way insert on the hose that connects to the fuel pump. Can I use a hose clamp on that to? Im not sure If I need to buy the hose with attached fittings from Delorean or just use fuel hose line and hose clamps.
Thanks in advance

[DMC5180]

Yes, but it must be Gates Barricade Fuel injection hose. Napa sells it by the foot. What I don’t recall is the size I used. 1/4-6mm or 5/16-8mm. They also have the correct type of clamps for the hose. Do Not use a worm clamp.

Most of the vendors provide this type (brand) of hose with there fuel pump replacement kits these days.


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[coreydmc]

Thanks for the reply Dennis. Car is stuck in my driveway and would like to get it back together today. I’m headed to Napa soon. I’ll ask for the gates barricade hose. I’ll take a piece of the old with me for size. Can you describe the clamps your talking about? Are they compression fitting or tighten with a screw driver?

[coreydmc]

59527 like this?

[DMC5180]

Thanks for the reply Dennis. Car is stuck in my driveway and would like to get it back together today. I’m headed to Napa soon. I’ll ask for the gates barricade hose. I’ll take a piece of the old with me for size. Can you describe the clamps your talking about? Are they compression fitting or tighten with a screw driver?

They are the screwdriver type, just the ask them for the correct line clamps. I ended up with a small assortment pack and used the ones that best fit the hose OD.




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[DMC5180]

59527 like this?

Yes


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[DMC5180]

How is the pump cover holding up for you?


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[coreydmc]

Pump and cover are great. Just the 2 hoses are bad. I think they were chewed by a mouse. I pulled the pump out of the tank. On the bottom there is a small hose that looks like it goes no where is that the overfill to put fuel back in the tank?

[David T]

Just because the outer covering is cracking off does not mean they were leaking. The hoses may not be the source of the leak. If the tank was filled to the brim there are other things that could be leaking. The hoses won't leak if the motor is not running but other tings can leak like the fuel sending unit or the pump boot. The small hose going "nowhere" is supposed to go to a clip and dump into the baffle.

[DMC5180]

Pump and cover are great. Just the 2 hoses are bad. I think they were chewed by a mouse. I pulled the pump out of the tank. On the bottom there is a small hose that looks like it goes no where is that the overfill to put fuel back in the tank?

A couple photos of the old hose would help. Theses cars are old enough now that many have had the hoses replaced at least once already, especially if it had multiple previous owners. The Original factory hose had an outer jacket that would deteriorate and fall off the inner hose core. It looked bad. But most of the time they didn’t leak.


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[coreydmc]

Here are the pics. They were replaced by PJ Grady 10 years ago

[David T]

They do look like PJ Grady replacement hoses but they don't look like they are the source of the leak. From the pictures it could be the fuel pump boot/cover and/or the fuel level sending unit. Is the tank full? Does it leak when it is, say, 1/2 full? Open the cover boot and see if there is fuel in the pump boot. If there is, replace the boots or maybe there is a leak at the fuel pump connections. Check the rubber gasket for the fuel sender and make sure the ring is tight. Put a dab of silicone on the rivets on the fuel level sender, they can leak.

[DMC5180]

You may want to replace those hoses anyway as a preventative measure even if they aren’t the source of the leak.

This is what happened to mine this past September about a a mile from my house. My lines were about 20 years old.

https://uploads.tapatalk-cdn.com/20190324/a4ddf107e5d29f2d7a660330f249d38e.jpg

The white piece on the fitting is the inner hose member.



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[coreydmc]

To bad I can’t post a video. It is definitely the feed return hoses on the fuel pump leaking. The red ones in my pic. The red outer rubber is peeling away exposing the inner part of the hose. With the car running fuel is squirting out of the inner hose sheathing.100% confirmation it’s those. Are they 5/16” or 1/4”? I have been to 4 auto parts stores today and none have gates barricade. I found ArmorMark hose # 50087. It’s 5/16” for fuel injection systems. Will that work?

[David T]

It's possible the fittings were not put on correctly and that's why they failed. If you can't get the right hose do not substitute something that will not take the pressure. It also must be Ethanol compatible. Order new hoses form a Delorean vendor and if necessary they can ship overnight. You will get the right stuff and quicker than trying to find or order the wrong stuff locally.

[DMC5180]

As long as the hose says SAE 30R14 T2 you should be good.



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[Ron]

I have been to 4 auto parts stores today and none have gates barricade. I found ArmorMark hose # 50087. It’s 5/16” for fuel injection systems. Will that work?They don't have to be Gates brand:

"SAE 30R6 hoses are designed for low-pressure applications like carburetors.
These can also be used as an emissions hose.

SAE 30R7 hoses are designed for fuel.
These can go under the hood and are typically used for low-pressure applications.

SAE 30R9 hoses are designed for high-pressure applications like fuel injection and oil.
These are designed to stand up to the environment under the hood.

SAE 30R10 includes hoses that aresubmerged in fuel.
This type of hose is used inside the fuel tank and typically on the fuel pump module. This type of hose uses a special layer on the inside and outside to prevent the core layers from being saturated in fuel. But, don’t use it under the hood. R10 hoses can’t stand the heat."

[Ron]

As long as the hose says SAE 30R14 T2 you should be good.

+1

SAE 30R14 T2 has twice the working pressure (255psi v/s SAE 30R9 100psi).

[coreydmc]

59533
How important is it to attach the fuel hose to this threaded coupling? Is there that much pressure that it needs to be threaded with the flared coupling? I have been trying for hours and no matter what it leaks. I don’t have enough room left on the rigid pipe to cut it and make a new flare to seal tight. I wanted to slide the threaded part back and just slide the hose 1” over the flare and than use a hose clamp. The flare only turns and will not slide back when pushing the hose over it. That way the flare is tapered and will create a tight seal over the hose and than use a hose clamp. Thoughts.....

[Bitsyncmaster]

One of those hoses is the supply line which has to withstand 75 PSI (more just to be safe). The other line is the return line that has no pressure. So the return line is not as critical like the supply line.

[coreydmc]

Figures the line coupling that is leaking is the feed.
Can someone recommend what I should do now? I don’t think I have the room to cut it off and re-flare. It actually doesn’t look flared. Is this line flared?

[DMC-81]

59533
How important is it to attach the fuel hose to this threaded coupling? Is there that much pressure that it needs to be threaded with the flared coupling? I have been trying for hours and no matter what it leaks. I don’t have enough room left on the rigid pipe to cut it and make a new flare to seal tight. I wanted to slide the threaded part back and just slide the hose 1” over the flare and than use a hose clamp. The flare only turns and will not slide back when pushing the hose over it. That way the flare is tapered and will create a tight seal over the hose and than use a hose clamp. Thoughts.....

It is important. I wouldn't do what you suggested. At minimum I would find an appropriately sized hard line to hose barb solution.


Figures the line coupling that is leaking is the feed.
Can someone recommend what I should do now? I don’t think I have the room to cut it off and re-flare. It actually doesn’t look flared. Is this line flared?

I can't tell by the picture, but it seems to be a similar compression fitting as the one I just had apart on the return line in the engine compartment. That used an olive/cutting ring/bulk ring (106980) and a Metric Tube Compression adapter (106994). The size of the return hard line was 8 mm. If it is the same type of ring, it is not a flare. When the ring is compressed, it cuts into the hard line thus making a seal. I was able to reconnect that line without it leaking. Basically I deburred, cleaned, and lubricated the ring/fitting. If you are interested, here is the thread:
http://dmctalk.org/showthread.php?17149-Replacing-the-Frequency-Valve-and-Return-hoses

I would try that first.

[David T]

It is a steel line. To stop any leaks you must get it VERY tight. A TINY smear of RTV can help if you have tried and it still leaks. Inspect thoroughly for any cracks. You should not have to cut anything. Try not to mess up, kink, or bend that line. To replace it you must remove the body unless you run a new, different one underneath.

[coreydmc]

It is important. I wouldn't do what you suggested. At minimum I would find an appropriately sized hard line to hose barb solution.



I can't tell by the picture, but it seems to be a similar compression fitting as the one I just had apart on the return line in the engine compartment. That used an olive/cutting ring/bulk ring (106980) and a Metric Tube Compression adapter (106994). The size of the return hard line was 8 mm. If it is the same type of ring, it is not a flare. When the ring is compressed, it cuts into the hard line thus making a seal. I was able to reconnect that line without it leaking. Basically I deburred, cleaned, and lubricated the ring/fitting. If you are interested, here is the thread:
http://dmctalk.org/showthread.php?17149-Replacing-the-Frequency-Valve-and-Return-hoses

I would try that first.

Now I am on the right rack. So my set up is the 8mm hard line and then the swivel nut # 106981 and then the olive cutting bulk ring # 106980, after that is the end of the hard 8 mm line. Is the end of the 8 mm hard line flared or does it shape itself when tightening into the fir tree connector #106982 which DMCH shows as not available
anymore?
Thank you

[DMC5180]

It is a compression sleeve. It cinches itself into the tapered seat of the fitting. A drop of oil on the threads will help the tightening process. Unfortunately, I don’t know what the correct B-nut torque is, but If I had to guess, about 15-17 lb ft.

I’m surprised you were able to separate the fitting from the line. Usually they won’t come loose from the from the line even though the nut is off.


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[coreydmc]

I’ll try some oil tomorrow that may help get it tighter. In the mean time I’ll order a olive cutting ring from Delorean tomorrow. I’m sure it will be hard to get the old one off since there is a groove in the 8 mm hard line keeping it from sliding off. Can’t use a dremel to cut the olive off because of sparks with fuel in the line and close to the tank....