The mixing elbow cracked on our Hunter 310 Yanmar 2GM 20F. We need to replace it. What should we expect? What complications are likely?
Mixing elbow cracked.
- Thread starter dirtman
- Start date
Shouldn't be a big problem. Take a look at HDI marine for a replacement.
hdimarine.net
Stainless Steel Exhaust - HDI Marine
Cast 316 Stainless Marine Exhaust Components - Engineered To Be Better
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If you are asking about the un-install, the existing elbow is attached to the exhaust manifold by a "connector" and a large, thin nut. It is probably rusted to the other parts and may require lots of PB Blaster or heat or cutting. You should expect to replace the connector and the nut, as well as the elbow.
Good luck.
G.
Good luck.
G.
All the advice you have been given here is correct. You will save yourself a lot of work by removing the entire elbow assembly from the 4 bolts holding it onto the heat exchanger, and removing the exhaust hose from it.
On my 340 the was no way possible to swing any type of wrench in that confined space to even try freeing the elbow itself. Spray the bolts with PB Blaster or similar product. Let it sit for a day and carefully unbolt the bolts. You don't want to break one off. Take your time. Once out and on a bench you can then put wrenches to it.
But if it was my boat, I'd replace the entire elbow with new and better materials.
I have some photos of my removal in albums under my name you can look at here on this site. There will not be much difference in your 2GM20F and my 3GM30F. And the connecting fitting has reversed threads on one side. You may not know whether it's the top side or bottom by looking at it. On a bench you can.
Patience and time and it's an easy process.
On my 340 the was no way possible to swing any type of wrench in that confined space to even try freeing the elbow itself. Spray the bolts with PB Blaster or similar product. Let it sit for a day and carefully unbolt the bolts. You don't want to break one off. Take your time. Once out and on a bench you can then put wrenches to it.
But if it was my boat, I'd replace the entire elbow with new and better materials.
I have some photos of my removal in albums under my name you can look at here on this site. There will not be much difference in your 2GM20F and my 3GM30F. And the connecting fitting has reversed threads on one side. You may not know whether it's the top side or bottom by looking at it. On a bench you can.
Patience and time and it's an easy process.
I've never had any problem removing a mixing elbow. After 20 years on my latest (3GM30F) it came off without a hitch. I don't know why you would have any problem having room for a wrench ... there should be plenty of space. Remove & replace, it doesn't get much easier. I'd replace hoses while you are at it ... very satisfying to replace old hoses, too.
A cracked elbow? 
How did that happen? People normally complain about the elbow getting clogged ...
How did that happen? People normally complain about the elbow getting clogged ...
Mixing Elbow Gasket
Hi all - I am replacing a mixing elbow and the U style part on my 2GM20F. I have removed the old corroded parts and now need to reattach the new parts (elbow, gasket, u style part and the connector). Here's my question, due to the access in the engine compartment I can't scrape off some...
forums.sailboatowners.com
See #3
Getting that Darn Mixing Elbow Off
I am having the hardest time getting the elbow off.. See Pic.. Do I remove the elbow or the flange that's connected to the engine? Even tried hitting it with a hammer. Any ideas? Thanks! -Jon
forums.sailboatowners.com
See #5
Too many old posts to search out.
NOTES:
Remember connector has both CC and CCW threads.
Use parting compound on stud threads.
Use lots of parting compound on graphite gasket
Flange faces must be absolutely clean. Use a razor sharp wood chisel.
Use a hair drier on exhaust hose to soften.
Use parting compound on interior of exhaust hose.
Look through reams of material on 2GM20F mixing elbows on this site.
If the elbow is cracked, I guess I wouldn't bother removing the elbow at the coupler, since that's the difficulty. I would replace the whole thing, flange and all.
Maybe not.
The flanged part is:
1. Expensive.
2. Massively thick.
3. Is not subject to corrosion.
3. Contains only loose carbon deposits and no salt.
Attachments
Trust me: if you buy the HDI mixing elbow, buy the whole deal: the mixing elbow, the manifold, and the threaded pipe in between. Ask me how I know:
My old parts looked almost new, and there was no way I was getting them apart. I used a torch, PB blaster, and a 5 foot breaker bar, and all it got me was a broken vice*. Just buy the whole thing and be happy you're not paying a mechanic.
* I do have a really nice new vice now! But the one that belonged to my grandfather has gone to the recycling center, which made me a bit sad.
Time for the Monthly Mixing Elbow Question...
I have a 17 year-old Yanmar 2GM20F with really low hours: maybe 400. I've been getting just a whiff of exhaust smell now and then: nothing definitive, but enough to make me wonder. I've never had the mixing elbow off before, but for the past few years, there's been an odd rust spot on the side...
forums.sailboatowners.com
My old parts looked almost new, and there was no way I was getting them apart. I used a torch, PB blaster, and a 5 foot breaker bar, and all it got me was a broken vice*. Just buy the whole thing and be happy you're not paying a mechanic.
* I do have a really nice new vice now! But the one that belonged to my grandfather has gone to the recycling center, which made me a bit sad.
Yes it is. Replacing any of the castings is expensive. I looked into replacing the back end of the heat exchanger and changed my mind after finding the price.
I should clarify that I've never had a problem removing the whole assembly at the flange. I've never had cause to remove the elbow at the coupling. Sure enough, the elbow isn't getting removed without taking the assembly out to work on it.
Since his elbow was cracked, I'd assume he read a few posts and has it worked out by now! Little time for reading & responding when it needs to get fixed to go sailing!
