American Diesel/Lehman 135 Lift Pump Fitting

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DBG8492

Senior Member
Joined
Jan 16, 2023
Messages
281
Vessel Name
Sovereignty
Vessel Make
1986 Marine Trader 36 Sundeck
The inlet fitting on my lift pump has been seeping diesel.

I thought it was the hose, so I was going to replace it today.

When I got the hose off, I found the fitting was loose - and that's what was seeping - so I pulled it off to check it and it's a male flare. I'm betting it's not supposed to be a flare - like someone used it in an emergency, but I'm not sure so I figured I would ask before loading it up with Megaloc and reinstalling it.

Anyone?
 
Saw this post on a search:


Wondering if it's the same deal and the old o-ring just wore out.

It looks like this:

1716651382707.png
 
Well - I took the old fitting with me to Ace - and the one here doesn't have a thing where you can test the fitting to see what size and thread it is.

Instead I dug through the other fittings that had female flares - it fit none of them. What it DID fit was a 1/4 FIP. So I bought a 5/16 X 1/4 MIP fitting and it won't fit the lift pump.

So I covered the threads of the old fitting with Megaloc and tightened it up, then put the new hose on with four clamps and primed it. Gonna wait and see if it seeps.
 
Last edited:
hmmm!!!
interesting
have a Westerbeke 30B
replacing my fuel pump found the same situation.
Could not figure it out.
Equipped with an original 90 degrees elbow and looking inside (female fitting) could see a flared setting.

Not sure what to do, decided to replace the original elbow for a regular pipe treading and a regular pipe treading male fitting matching the female tread on the hose ending.
Used a tread sealant.
 
checking on line found

And then Amazon has

URO Parts 06E127065G Fuel Pump Fitting, One time use fitting for GDI pumps​


caught my attention the lack of orings cited as well as the use of compression sleeves and the description
"one time use fitting"
 
I got it.

I'm a moron.

The "flare" fitting on the pump is not really a "flare," - the threads are NPT - with a taper - and the threads on the fitting I purchased are IPS - no taper.

So any NPT fuel line fitting from any auto parts store should work with pipe dope.
 
Well - I was wrong again apparently.

Just heard from Brian at American Diesel - on a *holiday weekend* no less...

He said:

The inlet fitting is indeed slightly special. The fuel lift pump inlet and outlet sizes are 5/16" SAE (Standard Automotive Equivalent) <Recesses> flare, thus deeper than a standard SAE fitting, but with the same thread and flare. The hexagonal flats will need to be "relieved" in order to allow the flare to "mate" as the threads are not sealing the inlet.

So the fix is (if I'm reading that right) to file down the inside flat edges of the hex so the male flare will insert far enough into the fuel pump to fully mate with the female side. The threads don't seal anything in and of themselves.

I'm wondering if the whole reason mine was loose and leaking in the first place was because someone had pulled it and covered the threads in Teflon tape - a lot of it in fact - way too much... Once that degraded over time, it left the fitting loose because it was never fully tightened.

I went ahead and re-used the original fitting with only Megaloc thread dope and tightened it up pretty good. I didn't stand on it, but maybe 10 to 15 ft-lbs. I won't turn loose with my fingers... Then I put everything back, changed the Racor filters and secondaries and bled the system. No leaks. Can't run it because we're on the hard, but once back in the water next Friday, I will run it and check for leaks. If it's leaking, I will try taking it off and filing down the flats. But given how old it is, I may have to order a new one and wait on it to arrive...
 
For anyone else who has this problem, call Brian at American Diesel and order part number 844-0278A.

$10 plus shipping.
 
I ran into this problem a few years back days before heading off on vacation. Took several fittings into a machine shop along with the fuel pump and had them chuck the fittings into a lathe and turn back the hex until it cleared. I keep two as spares on board.
 
Yeah having spares sounds like a good idea for sure.
 
If you haven't heard of Brian Smith, which I guess you haven't since you are here, you should call Brian Smith at American Diesel.
He has all the answers, his dad made FL engines, and he carries all the parts.
Check his phone number at the web site americandieselcorp.com.
 
I was helping a friend install a new pump on his Perkins and we had the same problem. We added an O-ring to the fitting and this worked fine.
 
If you haven't heard of Brian Smith, which I guess you haven't since you are here, you should call Brian Smith at American Diesel.
He has all the answers, his dad made FL engines, and he carries all the parts.
Check his phone number at the web site americandieselcorp.com.

Please read the third post back from this one.
 
For anyone wondering, a new fitting fixed this issue. Brian at American Diesel sells them for $10 - get spares.
 
Well - I took the old fitting with me to Ace - and the one here doesn't have a thing where you can test the fitting to see what size and thread it is.

Instead I dug through the other fittings that had female flares - it fit none of them. What it DID fit was a 1/4 FIP. So I bought a 5/16 X 1/4 MIP fitting and it won't fit the lift pump.

So I covered the threads of the old fitting with Megaloc and tightened it up, then put the new hose on with four clamps and primed it. Gonna wait and see if it seeps.
Flare are typically referred to as JIC fittings (joint international council). "O" ring fittings are ORB (O ring boss)
 
Flare are typically referred to as JIC fittings (joint international council). "O" ring fittings are ORB (O ring boss)
Try either a plumbing supply or industrial fittings supply house (F W Webb perhaps). I wonder if McMaster would have them?
 
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