Ford Lehman hole in exhaust manifold

[Tangler]

1977 80hp hole in manifold just where the elbow flange connects to the manifold...1" x 1/2 inch ...1) can it be welded (caste) ? 2) I have the basic manual but no instructions on repair of dismantling. unlike a car there are cooling hoses and pipes from the tranny and oil coolers attached to the elbow and manifold and other sources. I assume this all has to come off?. no water leaks from the hole...only exhaust . Any ideas about removing bolts that have been there since 77?...any other advice is appreciated. pic attached

 

[RT Firefly]

Greetings,
Mt. T. NO PIC SEEN?????? In general, when dealing with nuts and bolts that have lived in the same place since '77, try soaking the offending fasteners with a good penetrating oil first (may take numerous applications over several days). I have had some success with one of these to encourage stubborn nuts...
Sears.com
If all else fails, heat with a torch ONLY if you know what you're doing. If not, hire a professional.

 

[Tangler]

Thanks RT...what about gaskets? suppose I will have to cut new ones...

 

[sunchaser]

Sounds like time for a total replacement and not a patch job. 37 years is pretty good for a marine elbow/manifold. Call up American Diesel and they can steer you towards a new elbow or manifold. While you're at it change out all the connection pipes and hoses too. There are several good yards nearby, you may want to get an estimate for the overall job. Removing some of the old bolts can be a chore unless you are skilled and able to do it, namely the rusted in place bolts that may well need easy outs and rethreading.

 

[Tangler]

Sunchaser...a new one is $1500 from Bomac...thats alot of diesel...actually its not a lot of diesel and thats the real crime here

 

[jleonard]

Two years ago I went to replace my elbow and found that the manifold had rusted thru I think where you are describing. It was not quite that large of a hole though.
I had to remove the manifold to get the bolts out (actually only one bolt)
To fix the end of the manifold I had a machine shop mill the surface until it cleaned up.
I think the shop charged me $50 for the work
There is a lot of material on that manifold, so see if you can find a automotive machine shop to do the job.
And you can get all thegaskets at adc.

 

[RT Firefly]

Greetings,
Mr. T. For the life of me, I can't see where the problem is with the manifold. The elbow looks "iffy" but the manifold looks OK. Old age, eyesight failing.....

 

[Tangler]

RT! good spotting! ya got me dead to rights...the pic is of my starboard engine manifold as an example of where it hurts...the actual damage is on the less accessable port engine manifold...of course!#@&* best view is this from overhead..upper right dark area and under hoseclamps is black residue blown thru by hole. you can see tranny cooler etc.

 

[Tangler]

even better..you can see the end of the manifold here and all the mess under it

 

[Brooksie]

Soak the 4 bolts/nuts and tap them lightly over a period of several days then try them with a good fitting box wrench until you can work them loose. If they won't move more soaking and tapping. If still no go' heat as mentioned above.

Close the seacock and remove the exhaust hose & clamps and the saltwater hose & clamp.

It may turn out you just have a bad gasket but you can't tell w/o getting it opened up.

 

[RT Firefly]

Greetings,
Mr. T. I think Mr. Brooksie has nailed it-bad gasket. At least that's what my money is on until you start an autopsy. Not terribly likely the manifold is holed but anything is possible. Let's reserve judgement and hold off on ordering any gaskets until that sucker is laid open.....Both Bomac and AD should have gaskets on the shelf. Might have to install 2.

 

[BobH]

Try to use a six point socket, not twelve point.

Bob

 

[Tangler]

bad gasket would be too easy..1/2" thick gasket? I can get my thumb in there...gaskets not that thick is it?...but hole does feel very square..curiouser...a rotted hole would be jagged ...I will party tonite and go to the boat tomorrow to check further and soak bolts with penetrating stuff..always good suggestions on the forums..thanks guys and Happy New Year!

 

[BruceK]

I bought elbows for my 120s from FredWarner1 on Ebay, worth a try, about $180 I think. Came with gaskets, certainly not 1/2" thick. Waiting for the elbows, I sealed the leaks with the 2 stick underwater setting epoxy putty. Story ends there, elbows were fitted by the mechanic as part of other work.

 

[rochepoint]

Just had a quick look on Ebay..............
Ford Lehman 120 80 Exhaust Elbow 3" 1A372 FOR Marine Diesel Engine Manifold | eBay

Hope this helps...

 

[BruceK]

Just had a quick look on Ebay..............
Ford Lehman 120 80 Exhaust Elbow 3" 1A372 FOR Marine Diesel Engine Manifold | eBay

Well spotted, that`s the guy, I would happily deal with him again..

 

[River Cruiser]

A cast iron manifold can be repaired by brazing, I've repaired many over the years. Not a job for a rookie but a experienced welder should have no problem.

 

[Ben]

Tangler,

From your pictures this looks like the elbow. If so, I had a similar issue. The wet exhaust had eaten through the bottom of the elbow. I am a rank amateur, but was willing to try the replacement. The elbow cost me about $130. Hose pipe and fittings another $50. Time and fear I handled with tequila. Called the mechanic, almost brought him in because of lack of confidence on my part. I went forth and replaced the elbow and gasket.

Again IF it is just the elbow. You know better than I. Pictured is my old elbow looking similar to yours...

 

[Tangler]

looks about right...loosened the elbow flange bolts today to the point where water started to drip out...how much water can I expect? sea cock closed...cant see any anti siphoning device to stop any water coming back from outside..?? does the coolant need to be drained or is that a different system altogether? as you may have surmised I have never opened a marine exhaust system...

 

[RT Firefly]

Greetings,
Mr. T. Damn that memory. I forgot about the coolant escaping after the elbow is loosened. At least I think it should be coolant. Sorry.

 

[psneeld]

Usually no coolant...it's dry at the neck on a Lehman. From the pic in post 15 there is no coolant holes in the Lehman flange so it should just be injected saltwater.

If you have water dripping out from just loosening the flange bolts...you may have bigger problems...the water injection is downstream and none should be back at the flange.

 

[RT Firefly]

Greetings,
Mr. psneeld. As bad as my memory is I seem to recall coolant leakage when I did an injector elbow on a 120. You're absolutely correct that raw water is downstream of the flange and would signal "bigger problems".

 

[Xsbank]

That exhaust manifold is cooled with coolant, but I don't think that elbow is. I am only willing to offer the caution about Lehman coolant, there is a bleeder valve on the top of the engine that MUST be bled after you fill the coolant up afterwards, with the engine running.

 

[RT Firefly]

Greetings,
Mr. X. I concur. The manifold must be bled after filling but I don't think it's with the engine running. One of my morning ER checks is to open that valve with the expansion tank cover loosened to release any air entrapped at the upper end of the manifold. Please correct me if I'm wrong.

 

[psneeld]

Greetings,
Mr. X. I concur. The manifold must be bled after filling but I don't think it's with the engine running. One of my morning ER checks is to open that valve with the expansion tank cover loosened to release any air entrapped at the upper end of the manifold. Please correct me if I'm wrong.

Absolutely correct...engine NOT running to use the bleed valve....

Everyone...check your manuals...too much bad info floating around the internet these days!!!!!!!

 

[Xsbank]

Hey RT, I think you're correct. I remember paying lots of attention to the bleeder in the past but I guess I had forgotten about the running part. I also recall that I installed the American Diesel overflow tank mod which not only stopped the expansion tank from blowing coolant in the bilge, it kept the expansion tank full and removed the necessity to continuously check the bleeder.

Sorry if I can't live up to your expected level of perfection Mr. psneeld, I'll try and do better next time, or perhaps I should just send you my comments first for vetting?

I'm beginning to see why Marin only PMs when he contributes. While I couldn't remember if you would find coolant with the elbow off a Lehman, I was trying to help out someone with a problem, who was going to have a low-coolant issue. Excuse me.

 

[psneeld]

Hey RT, I think you're correct. I remember paying lots of attention to the bleeder in the past but I guess I had forgotten about the running part. I also recall that I installed the American Diesel overflow tank mod which not only stopped the expansion tank from blowing coolant in the bilge, it kept the expansion tank full and removed the necessity to continuously check the bleeder.

Sorry if I can't live up to your expected level of perfection Mr. psneeld, I'll try and do better next time, or perhaps I should just send you my comments first for vetting?

I'm beginning to see why Marin only PMs when he contributes. While I couldn't remember if you would find coolant with the elbow off a Lehman, I was trying to help out someone with a problem, who was going to have a low-coolant issue. Excuse me.

Or you could have done like I usually do and LOOK IT UP before I post it with a link or cut and paste to support my post....the "I think its right" posts only help people when they are correct.

It only took me a few seconds to go back and look at the flange picture to see that there's no coolant holes in the one posted in the post I mentioned and I know there isn't any in the stainless one I have. Wild a**ed guesses which are so prevalent here in TF do no one any good...better to be a spectator than wrong.

I too make mistakes...that's why I tell people to check their manuals...

I just like to make fewer mistakes than most....so sure run them by me first.....

 

[Xsbank]

Sleep well everyone, the internet is no longer in peril.

 

[psneeld]

Actually it is...I just LOOKED IT UP......
Don’t get spun by Internet rumors.

 

[Tangler]

hmmm...lots of good tech info now, the kind I really need...thanks all..interesting debate too...hope there is no hard feelings out there..all info I get on the forum is verified by myself before accepting advice as gospel...I think we all need to be careful with what we read from any source. That being said, I have always got great advice on TF and appreciate all comments..back to the boat tomorrow to have another go at it.