Lehman exhaust elbow

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Trawler Sandpiper

Veteran Member
Joined
Mar 5, 2015
Messages
40
Location
USA
Vessel Name
Sandpiper
Vessel Make
1976 Marine Trader D/C
Hi, I am in the process of replacing the exhaust elbow on my 120 Lehman.
Have been able to break loose the top two bolts but the two bottom ones are frozen. Besides the usual things like applying heat and such, any other ideas before I break out the impact gun?
This is being done because I found a coolant leak where the elbow joins the exhaust manifold. So I guess the manifold is suspect but hoping it's the elbow(which is pretty ratty) or the gasket.
 
I'd go along with Capt. Bill, if you put a socket wrench on the frozen nut with a 'T' piece, give the head of the 'T' piece a couple of cracks with the hammer while you have the 'T' bar under tension loosening the nut. If that doesn't work ask around if anyone mechanically minded has a nut splitter, or buy one and keep it future use.
When you reassemble use Copperslip anti seize compound to prevent the same trouble in the future.
I assume you know that the Lehman is based on the Ford base engine.
 
Greetings,
Mr. TS. Welcome aboard. I'd be VERY careful about giving ANY piece of cast iron a whack with a BFH. Repeated heating and cooling of the bolt heads to dull red hot would be my plan of attack along with GENTLE tapping of the bolt head during heating and cooling cycles. Patience, Grasshopper...
 
Yesterday I just used a nut splitter for the first time on a bracket that I was trying to remove from the engine mount frames. What a pleasant surprise. The nut came off in pieces and the bolt was undamaged. I was careful not to crank the splitter down to the point of damaging the threads of the bolt. If they are replaceable bolts then it does not matter. The trick is, can you fit it into the area that you are working.....
 
What you do not want to do is damage the manifold itself. They are no longer available new (unless some company has started making them as an aftermarket item). Replacement exhaust elbows are readily available from American Diesel and exhaust specialists like National Marine Exhaust can make up a new one.

But according to Bob Smith at American Diesel, the only way today to get a replacement Lehman manifold is to get one off an engine that's being parted out.

The photo below is of one of our exhaust systems with an American Diesel elbow.
 

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Ease of the impact wrench, it'll just snap them. brush diesel on them for a few days, it's a great solvent.. Don't try to undo,tighten fractionally first, then they'll come free.
 
Nut splitters are great. Unfortunately he's working on bolts. :D
Now who is being a nut splitter....:eek:....:D

Also awhile back someone else posted that acetone and ATF mixed 50/50 won all penetrant contests beating PB Blaster, Liquid Wrench and 3 in 1 formulas for freeing up frozen fasteners.
 
Greetings,
Mr. TS. Welcome aboard. I'd be VERY careful about giving ANY piece of cast iron a whack with a BFH. Repeated heating and cooling of the bolt heads to dull red hot would be my plan of attack along with GENTLE tapping of the bolt head during heating and cooling cycles. Patience, Grasshopper...

Seems you have your wisdom back if not your energy yet....pasta help?:D

Just tied up in St Marys at the free dock (6 hr limit posted)...nice little town not to be missed, but like Darien is up a river with good current...fortunately only about 2.5 miles instead of 7.
 
We're talking taps with the hammer while the wrench is under tension to release the nut/bolt, not a hefty redneck wallop to do damage.
In a worst case scenario you can get another manifold from Bowman engineering or through Mike Bellamy at Lancing marine.
Obviously try all other methods for a good result before resorting to Redneck engineering.
If it were me I'd make damn sure when you refit it that the next time it needed to be off it would come off easy.
Patience and you'll win the day.
 
Now who is being a nut splitter....:eek:....:D

Also awhile back someone else posted that acetone and ATF mixed 50/50 won all penetrant contests beating PB Blaster, Liquid Wrench and 3 in 1 formulas for freeing up frozen fasteners.

I posted that. If he made a well out of clay around the bolt head so the mixture could sit around the bolt head it might work. As well as tapping on the bolt head every so often as it sits immersed in the fluid.
 
I posted that. If he made a well out of clay around the bolt head so the mixture could sit around the bolt head it might work. As well as tapping on the bolt head every so often as it sits immersed in the fluid.
Sorry.... couldn't remember if you posted the acetone/ATF mix as a penetrating fluid or in the drinks and appetizers section....:D
 
Best penetrating oil I've tried is "Mouse Milk", I got mine from an airplane parts store. Again the secret is patience, apply "Mouse Milk" at intervals over several days, don't break the bolt or round off the nut/bolt head by trying before it is ready!
 
Thanks to all for the replys. Tried the heat method to no avail. Decided instead to pull the manifold and let the machine shop get the elbow off. Manifold removal was non remarkable. It looks pretty good, of course the "elbow end" is still an unknown. I kinda look at this as the glass 1/2 full as I will have the manifold inspected and reconditioned. Already have the replacement elbow ready to go. Now, can anybody recomend a shop that reconditions manifolds in the Ft. Lauderdale area? Thanks again everybody!
 
Call G S Marine (954) 523-2125

3040 SW 4th Avenue
Fort Lauderdale, FL 333153015

I've got a SS exhaust elbow for a 135 Lehman laying around that should fit a 120 if you're interested?
 
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Thanks but already purchaced a replacement. A 1A283, ending in 3"NPT.
Found one of those since I have a 45* stainless NPT. pipe to the muffler after the elbow.
However will check out CS Marine tomorrow.

Thanks, Doug
 
Thanks to all for the replys. Tried the heat method to no avail. Decided instead to pull the manifold and let the machine shop get the elbow off. Manifold removal was non remarkable. It looks pretty good, of course the "elbow end" is still an unknown. I kinda look at this as the glass 1/2 full as I will have the manifold inspected and reconditioned. Already have the replacement elbow ready to go. Now, can anybody recomend a shop that reconditions manifolds in the Ft. Lauderdale area? Thanks again everybody!

3 years ago that is what I also had to do, remove the manifold. I took it to my son's auto repair shop and he got the remaining bolt out on about 10 seconds with an acetylene torch and vise grips. The elbow end of the manifold was corroded so another automotive machine shop milled the manifold shorter by about 3/16 inch to get back to solid iron again.
 
I had the same problem on my pair of Lehman 120's. In my case the bottom two bolts came out easily while the top two were frozen. I gave up and had a yard extract them but I do not know how it was accomplished. My plan going forward was to unbolt them every six months or so and reapply an anti-seize compound. I use a product called Kopr-Kote. However, I am re-thinking.

How about this as an alternative? Replace the bolt with a threaded stud and use a nut as the fastener and still use an anti-seize compound. Should the nut later become frozen, a nut-splitter will take care of the problem. Since the mating surface is gasketed, I can't see any disadvantage using a stud and nut. Opinions?
 
It is nice to see that straight run of reinforced exhaust hose from the ell to the muffler. I had to replace my elbow last year and I had no problem getting the bolts off but could have , (no, I did kick myself) for cutting the reinforced 22" piece of 3 1/2" rubber hose off and due to the compound angles involved I spent 2 d I ays getting the new piece of stiff hose trained and seated properly again. Wish I had taken photos of all the steps I went through to finally get it there.

Glen
 
Exhaust Elbow removal - BPH nightmare

While my method of exhaust elbow was effective - it destroyed the elbow casting. Good for me because it was rusted through. One of the bolts was frozen in place after 30+ years of use. So I gave two good whacks with a 2 pounder and the casting split. Now i have full access to the stubborn bolt and an old elbow in two pieces. Replacement new elbow purchased from Harbor Marine in Everett WA. They have a Ford Lehman engine expert FYI.
 
Thanks to one and all for the tips, however it turned out that the exhaust manifold as well as the elbow was shot. I replaced everything with a Bowman manifold / heat exchanger / header tank in one unit. I finished the install today in fact. While I wouldn't say it was easy but it was not impossible. That is if you have another person assisting.
 
The tip about checking the elbow exhaust bolts once every six months is an excellent idea. Thank you. I found two of mine almost frozen. If someone knows of an affordable stainless alternative to the original elbow, please let me know. The listed gs marine one doesn't have it. Thanks
 
Try contacting Mike Vogt at Harbor Marine. His email is harbormarine@hotmail.com
This is where I source by CI elbow. They rebuild Ford Lehmans.

Bruno
 
I replaced my port elbow on a 120 2 wks ago. 2 came out with a breaker bar after using oil. One, the head of the bolt snapped off leaving a stud (best scenario). A good quality bolt puller brought it out w/o a problem. The 3rd one was froze stiff. Oil, language, tapping with LFH (using the ball side of the hammer, lightly). Two days was long enough :mad:!!! Out came the breaker bar! Out it came :blush: I re-tapped the holes, new bolts coated with anti-seize. Life is good. Starboard is waiting for the day I'll pick up a fresh bottle Medicine.
 
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