Ford Lehman 120 fuel return line?

[Tazling]

Hi folks. The story of my new old GB32 seems never to end, still trying to get the engine into travelling condition -- I don't know when I will ever get to actually enjoy the boat!

Anyway, after a head gasket job this Spring it appears the mechanic was a bit careless putting everything back together. (He was having some serious medical issues and I'm not dissing him, I think he was on a bit too much pain meds at the time.) There is a big fuel leak from the fuel return line where it comes out of the head, going to the filter. Like 2 litres and more over just a few hours of motoring.

Fuel is running down the outside of the line and dripping off onto lower bits of the engine and hence into the (thank goodness) stainless drip pan installed by some right-minded previous owner.

This line is the only flexible (braided) line on the engine. I haven't really seen braided fuel lines on a marine diesel before so wondering is this original, or a replacement part installed by some previous owner?

Tried tightening that banjo fitting (carefully) and that didn't fix it so I fear the mechanic may have put the old copper washers back in, which I read online you are not supposed to do. Or maybe the line itself is compromised. I am not a real mechanic -- know just enough to get myself in trouble -- so I was wondering if you all could give a few words of advice and help with specs.

Does anyone know the size -- SAE I assume -- of banjo fitting used here? And is the braided fuel line a standard item that I could get from any parts store, or some special American Diesel thing? Are the copper washers a specialty thing or can I get them from any auto parts store?

 

[Bmarler]

No replies yet is see. I don’t have a Lehman but I can say this, the copper washers can indeed be had a any good auto parts outlet. Like Napa, or similar. Alternatively, you can order an assortment online for reason money.
I’m not surprised about the flex line on the return, it’s not high pressure. I bet you just have a bad seal on the banjo and a new copper (or aluminum) washer will seal it up.
If you can’t find a washer, you can heat the one you have re soften it.

Here’s a link to an alternate style of washer. I use these on my low pressure lines on the filter housings.
https://www.summitracing.com/parts/...ePD_D61jggg0xj4yI2dPQaOgMrIqWUlhoC4BkQAvD_BwE

 

[DavidM]

Heat the washers on your stove’s burner or with a propane torch. While still hot, drop them in water. Softens them up almost good as new.

David

 

[DennisB1]

Hydraulic supply companies sell braided high pressure hoses that are rated for use with fuels Parker-hannifin, Eaton and others make the hose. They also have fittings. The banjo could be special. It would be best if you brought the old hose and fitting with you to assure getting the right parts. Good luck

 

[Marco Flamingo]

Be very careful with that banjo bolt. You can find them in metric, but some of the standard pieces are hard to find. I had to source them by buying brake parts for vintage us automobiles. Turns out it was cheaper to buy the complete brake line system then to buy a banjo bolt from some of the Big supply houses. Copper washers are available in assorted on Amazon in metric sizes. Turns out a banjo bolt doesn't care about a metric washer.

 

[kchace]

Good advice above. If the mechanic was “careless” or distracted I would also be concerned about the quality of his other work done at the same time. For example the bleed off pipe is INSIDE the valve cover and it has 7 connections. One at the top of each injector and one with a very tiny fitting into the rim of the head that is directly opposite the leaking banjo fitting. If any of those connections are leaking it will put fuel directly into the engine oil. At a bare minimum I would keep a close eye on the oil level (make sure it doesn’t rise) and probably want to have an oil sample tested after about 25 or 50 hours.

Ken

 

[Comodave]

We had SP225sin our last boat. The fuel return was leaking. Called Brian and he said they were no longer available but had a complete replacement system. Don’t remember exactly what it was but it worked great.

 

[PM]

That is a crushable copper washer, it should not be reused. They are easily sourced and replaced. I am more concerned about the volume of fuel through the return line. On a F.L. it is almost nothing, and there is very little pressure on the line, a leak is unlikely. You say the line runs to a filter, it should run to the fuel tank. If it is running through or to a filter something is not right. Depending on which filter and which side of the filter it is connected to you will be dealing with either suction or pressure, not right for a return fuel line.

Disconnect the line from the filter and plug the hole. Get a new washer and install it. Just for fun run the return line to a jug, you should see that you get almost no return fuel, then plumb it to your main tank.

pete

 

[Comodave]

As mentioned in post #3 you can anneal the washer and reuse it.

 

[Tazling]

About the rate of flow in the return... Brian at American Diesel said that the Hong Kong Grand Banks installation of Ford Lehmans was "weird" and "different." He sounded rather disapproving actually

Anyway if I can remember the gist of his enthusiastic gearhead TED talk, part of it was that the injector pump uses the diesel fuel to lubricate itself, so it pumps a lot more through than other types of injector pump, and hence there is more volume and pressure at the overflow. I have no idea (this is my first F-L) but he seems to be super expert so I expect he knows what he's talking about

 

[Tazling]

GOOD NEWS. leak fixed

So being unable to get hold of my mechanic (who has been plagued with serious medical issues for the last several weeks and is in and out of hospital, poor fellow) I tackled it myself. Ransacked all the old spare parts and bits in boxes and jars and by a miracle found a collection of copper washers for banjo fittings! and by a further miracle exactly 2 of them were the right size.

Very carefully loosened the banjo fitting on the head, and found that (Aieeee!) the banjo bolt was wearing only the last wispy, crispy remnants of an ancient copper washer. These had to be pried off with a knife tip, very carefully! The other side of the fitting had no washer at all, to my stupefaction.

Put bright shiny new copper washers on and very carefully tightened everything up again. Ran engine. NO LEAK! much rejoicing. Now I have to figure out what size those washers were (they were a Yanmar part) and get a few spares just in case.

It still bugs me that this braided fuel line is an irreplaceable discontinued part.... Brian at AD said that one of its fittings is an "eighth-inch Bundy which no one makes any more". I have no idea what he's talking about, but clearly some research is needed to make sure I can somehow find parts to reconstruct this ancient braided return line if it ever breaks.

 

[Tazling]

Be very careful with that banjo bolt. You can find them in metric, but some of the standard pieces are hard to find. I had to source them by buying brake parts for vintage us automobiles. Turns out it was cheaper to buy the complete brake line system then to buy a banjo bolt from some of the Big supply houses. Copper washers are available in assorted on Amazon in metric sizes. Turns out a banjo bolt doesn't care about a metric washer.

That is very interesting, you wouldn't happen to remember where you found the vintage brake parts by any chance?

 

[Tazling]

We had SP225sin our last boat. The fuel return was leaking. Called Brian and he said they were no longer available but had a complete replacement system. Don’t remember exactly what it was but it worked great.

Sorry, I'm an ignoramus still, what is an SP225 please?

 

[CharlieO.]

That is very interesting, you wouldn't happen to remember where you found the vintage brake parts by any chance?

I used them in building/fixing motorcycles too.

https://www.dimecitycycles.com/brake-and-brake-parts/brake-line-fittings.html

I replaced my crusty return line with a nipple and rubber fuel line to the return port on my fuel valve. But I didn't have a banjo bolt set up any my engine.

 

[Mischief]

Hi folks. The story of my new old GB32 seems never to end, still trying to get the engine into travelling condition -- I don't know when I will ever get to actually enjoy the boat!

Anyway, after a head gasket job this Spring it appears the mechanic was a bit careless putting everything back together. (He was having some serious medical issues and I'm not dissing him, I think he was on a bit too much pain meds at the time.) There is a big fuel leak from the fuel return line where it comes out of the head, going to the filter. Like 2 litres and more over just a few hours of motoring.

Fuel is running down the outside of the line and dripping off onto lower bits of the engine and hence into the (thank goodness) stainless drip pan installed by some right-minded previous owner.

This line is the only flexible (braided) line on the engine. I haven't really seen braided fuel lines on a marine diesel before so wondering is this original, or a replacement part installed by some previous owner?

Tried tightening that banjo fitting (carefully) and that didn't fix it so I fear the mechanic may have put the old copper washers back in, which I read online you are not supposed to do. Or maybe the line itself is compromised. I am not a real mechanic -- know just enough to get myself in trouble -- so I was wondering if you all could give a few words of advice and help with specs.

Does anyone know the size -- SAE I assume -- of banjo fitting used here? And is the braided fuel line a standard item that I could get from any parts store, or some special American Diesel thing? Are the copper washers a specialty thing or can I get them from any auto parts store?

Are you sure both copper washers were/are installed?If you go to a injector/ pump shop, they will probably just give em to you. Take the banjo bolt with you.

 

[omoore]

Call Brian Smith at American Diesel. (804) 435-3107
They make a flexible return line. The original was a copper tube which cracked with vibration. I replaced my return. Very easy. No need for a mechanic.
Brian is extraordinary generous with his time. He has helped me many time. The company has everything you would ever need for your engine. Once you get past the teething problems, you will have a very reliable engine. Typically, they go 30k hours before rebuild. They are vulnerable to overheating. If you have not checked out your oil coolers, do it immediately. I replaced the cooler hoses --engine and transmission--as preventative maintenance. I should have replaced the belts as well. Had one break and the engine overheated. Fortunately, I got it shutdown without damage.
Enjoy your boat! Oliver

 

[Nepidae]

Ford Lehman

For ANYTHING Ford Lehman you should know about American Diesel.

Brian, the son of the developer of the FL runs the business now but he is as knowledgeable as his father was and can guide you on repairs and also has any part for a FL engine.

American Diesel 804-435-3107.

Be smart, go to the guy who actually knows.,

 

[SteveK]

post 11 seems to have resolved this thread issue.

 

[Comodave]

Sorry, I'm an ignoramus still, what is an SP225 please?

It is the 225hp version of the Lehman. Turboed and aftercooled.