Remove Universal 5411 exhaust flange

[Alsail27]

Hi everyone,
I am trying to remove the westerbeke mixing elbow and in order to do that I need to remove the entire assembly including the flange. The nuts came off the posts no problem, but after that everything is rock solid. Any thoughts on how to best remove this? I am using PBblast and will try heating the flange. Another thought is to use two thinner nuts and back one into the other to be able to unscrew to see if the posts will move ... But any advice would be great!
Thanks
Alex

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[kenbo]

Just tap the assembly aft with a block of wood and a hammer. Rust is a powerful adhesive. I would avoid trying to remove the studs, you'll have bigger issues. If you think getting the exhaust flange separated wait till you try to unscrew the flange from the mixing elbow.

[Engine man]

Drain the coolant first, or you may have an uncontrolled cascade. PB Blaster, as you have noted, is recommended. Now lift the exhaust elbow by hand, then press down on it. Repeat until it loosens. You may also tap it aft, hitting the elbow, using a short length of 2 x 4 wood. Many taps are preferred vrs heavy blows. Joe

Originally Posted by Alsail27

Hi everyone,
I am trying to remove the westerbeke mixing elbow and in order to do that I need to remove the entire assembly including the flange. The nuts came off the posts no problem, but after that everything is rock solid. Any thoughts on how to best remove this? I am using PBblast and will try heating the flange. Another thought is to use two thinner nuts and back one into the other to be able to unscrew to see if the posts will move ... But any advice would be great!
Thanks
Alex

Attachment 253223

[Stu Jackson]

Originally Posted by kenbo

1. I would avoid trying to remove the studs, you'll have bigger issues.



2. If you think getting the exhaust flange separated wait till you try to unscrew the flange from the mixing elbow.

1. Correct. You really don't want to remove those studs at this stage of the game at least until you get the flange off. Try really, really hard to not mess up the threads on those studs!!! There is a gasket between the flange and the manifold that you will have to replace. I use a small amount of gasket sealant on the flange side but never on the manifold side because you can clean the flange face when you next remove it, but it's hard to clean the manifold side.


2. Use a vice. You'll need one to reinstall it, too, to avoid blow by. It needs to be tight because of the type of threads.


PS - I've done this three times on my M25.

[Sailor George]

I have a 5432 universal engine with a Yanmar elbow. I found out the hard way that the elbow has a left hand thread where it screws onto the exhaust pipe from the engine. Just thought, if you had the same elbow, this would be of help. Please let us know how you make out. Good Luck

[Boatyarddog]

Originally Posted by Alsail27

Hi everyone,
I am trying to remove the westerbeke mixing elbow and in order to do that I need to remove the entire assembly including the flange. The nuts came off the posts no problem, but after that everything is rock solid. Any thoughts on how to best remove this? I am using PBblast and will try heating the flange. Another thought is to use two thinner nuts and back one into the other to be able to unscrew to see if the posts will move ... But any advice would be great!
Thanks
Alex

Attachment 253223

Try a dead blow hammer, wood block.
Advise: be sure you mark the pieces, so they can be assembled in the same position, before you try to replace the elbow.

There's a chance you'll not be able to get the flange unscrewed from the mixing elbow.
Lotsa heat.
Good luck!
Boatyarddog

[kenbo]

For the looks of the picture that pipe nipple is frozen into both the flangs and the mixing elbow. I wouldn't even try to unscrew them. The method that I have used with success is to cut the nipple in half and then with a hacksaw blade cut the nipple longitudinally being careful not to damage the female threads on the mixing elbow and flange. Now the nipple can be "crushed" and removed with a hammer and chisel.

[Boatyarddog]

Originally Posted by kenbo

For the looks of the picture that pipe nipple is frozen into both the flangs and the mixing elbow. I wouldn't even try to unscrew them. The method that I have used with success is to cut the nipple in half and then with a hacksaw blade cut the nipple longitudinally being careful not to damage the female threads on the mixing elbow and flange. Now the nipple can be "crushed" and removed with a hammer and chisel.

Be sure to mark The orientation of the elbow to the Flange.
It will be most difficult to change it once you reassemble.

If you use this method have handy a tap big enough to go thru those threads.
As, the threads will still have material enough to limit your ability to fully insert the new nipple.

Lots heat is the best, acetylene torch, rosebud tip.

It will be nessessary to check the flatness of the flange after this, probably just flat sand on a table/bench till it looks scratched up evenly.
Run a flat file over the Manifold side as well.
New gasket!
Boatyarddog

[kenbo]

Originally Posted by Boatyarddog

Be sure to mark The orientation of the elbow to the Flange.
It will be most difficult to change it once you reassemble.

If you use this method have handy a tap big enough to go thru those threads.
As, the threads will still have material enough to limit your ability to fully insert the new nipple.

Lots heat is the best, acetylene torch, rosebud tip.

It will be nessessary to check the flatness of the flange after this, probably just flat sand on a table/bench till it looks scratched up evenly.
Run a flat file over the Manifold side as well.
New gasket!
Boatyarddog

I've used that technique on high-pressure steam piping (excess of 150 psig) and never an issue without chasing the threads. I'm sure it'll work on the 2-3 psig found in the exhaust piping. You don't have to hacksaw all the wat though, just to the top of the female threads and have at it with a cold chisel and that nipple will fold like a house of cards. I'm also willing to bet the OP doesn't have a torch much less a rosebud.

[Boatyarddog]

Originally Posted by kenbo

I've used that technique on high-pressure steam piping (excess of 150 psig) and never an issue without chasing the threads. I'm sure it'll work on the 2-3 psig found in the exhaust piping. You don't have to hacksaw all the wat though, just to the top of the female threads and have at it with a cold chisel and that nipple will fold like a house of cards. I'm also willing to bet the OP doesn't have a torch much less a rosebud.

Most inexperienced DIYers will not complete this process without fkin it up!
I've been in the middle of those situations after the damage is done.
1-1/2" to 2.0" taps are expensive, so a machine shop will be a big benefit.

Should be a machine shop job, not for 1st timers that aren't sure how to tap a stubborn flange away without asking a forum.

Really just trying to save the poor fellow some un needed aggravationyou need a big vise too, and leverage.
And yes you have to cut the nipple 99.9% thru or it won't collapse.
Heat first will break the corrosion bond.

How it's done the first time is important!
Boatyarddog

[glenn.225]

If you get it off and choose heat to unscrew. Make sure you heat the side with the female threads. Before you heat it try a wet rag inside the the nipple to keep it cooler (greater temperature difference ) just watch for fire. Don't splash with water, cast iron may (slight chance) break.