Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

[natureschild88]

I'm replacing a torn exhaust tube bellow on my '91 Mercruiser 4.3 V6. The tube on the lower end of the exhaust elbow had a small tear in it that was leaking water (salt water at that!) on the back of my motor and starter. I bought a new replacement tube made by Sierra and I'm having a helluva time trying to get it to fit back on there.

The tube I'm replacing is #5 in the following diagram:
EXHAUST SYSTEM , USE WITH 4 INCH EXHAUST ELBOW-Performance Product Technologies

I removed the torn tube with a razor and took all of the hose clamps off of the upper tube (#1 in the diagram) to give me maximum flexibility. I have the elbow turned 90 degrees from the new tube and the new tube is pushed onto the lower exhaust pipe (#7 in diagram) about 1/2 way.

From here, I cannot get the elbow to spin back into the new tube. I've tried prying the tube with a long screwdriver and spinning the elbow into it, but I'm not getting anywhere. Is there something I can do to the tube that would make it more pliable and help the elbow slip back inside it? Or do I need to remove part of the exhaust manifold to get this thing back together?

PLEASE HELP!

 

[thumpar]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

If you have water coming in it is not the exhaust bellows that is the problem.

 

[natureschild88]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

In any case I need to replace this to get the boat back in the water for vacation on Wednesday.

Does anybody have ideas that could help me put this back together??

 

[theblob]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

In any case I need to replace this to get the boat back in the water for vacation on Wednesday.

Does anybody have ideas that could help me put this back together??

I had captain calls exhalst on mine when i had to replace the tube.i rubbed oil on mine and had to get mad at it and force both ways.make sure elbow is already where it should be when starting.i know with metal wire in tube its hard to move.get gloves use feet get mad.it was hard with captaincalls exhalst so probly harder with what you have.oil it good.

 

[theblob]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

Check make sure it's not too long,because i had to cut two inches off mine.might be good to double clamp too.im not professional,but know that stiff tube wont bend much.hopefully someone has another trick

 

[thumpar]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

You could run without the tube/bellows and be fine. You have other problems if you have water coming in.

 

[MarkSee]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

No, you should not need to take off the exhaust elbow to get that back together.

A can of Mercury/Quiclsilver Power Tune is known to work wonders on making rubber pliable enough to push the tubes on.
I would head to the closest Mercury dealer who should have 1 in stock or even West Marine may have it in stock.
MERCURY MARINE Power Tune at West Marine

I must admit I have not actually replaced those to know if it's easier/better to do the lower tube first then the upper or vice-versa so maybe someone will come along that can offer an opinion. I do remember though that on my 7.4 when my mechanic put my heads and exhaust back on all the exhaust was bolted together then he did those last.

Mark

 

[achris]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

From your diagram, and that was very helpful (I was thinking the same as most people, exhaust bellows, in the bellhousing)...

To replace that tube I would do the following...
1. Loosen all the hose clamps on that tube (#5), and the top two clamps on the tube (#1) at the end of the exhaust elbow.
2. Push the old tube (#5) all the way down the Y-pipe to expose the bottom of the aluminium tube (#3).
3. Remove the aluminium tube (#3) and the top rubber tube (#1) from the exhaust elbow.
4. Remove the old tube (#5) from the Y-pipe.
5. Coat the inside of the new tube (#5) with a thin layer of grease (any grease, doesn't matter)...
6. Slide new tube down the Y-pipe.
7. Slide old top tube with aluminium tube (#1 and #3) back onto the exhaust elbow.
8. Pull new tube (#5) up onto aluminium tube (3#).
9. Tighten up all 6 hose clamps....

Job done....
If step 2 if too difficult, then just cut the old tube off. You're replacing it anyway...

Chris......

 

[natureschild88]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

Thanks for the help, wish I had thought of grease earlier that definitely sounds like the right ticket. I'll give it a try tomorrow.

 

[MarkSee]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

From your diagram, and that was very helpful (I was thinking the same as most people, exhaust bellows, in the bellhousing)...

...hey, thanks for the complement mate; that's the link I gave him in his other thread about the torn tube.
I knew what the right part he was talking about....maybe us So-Californians are just in-synch

...and I did say someone would come along and offer an opinion.....10 minutes later you did....I need to go buy some lotto tickets....

Mark

 

[achris]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

...hey, thanks for the complement mate;

Most well deserved...

that's the link I gave him in his other thread about the torn tube.
I knew what the right part he was talking about....maybe us So-Californians are just in-synch

You know what they say... 'Great minds think alike'... (Or is it 'fools seldom differ' )

...and I did say someone would come along and offer an opinion.....10 minutes later you did....I need to go buy some lotto tickets.... Mark

Buy one for me too...

 

[hivoltg]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

WD40 worked for me on this job and it washes off after its in place. Its the only job on a boat that I would recommend wd40 for. No wd40 hating...its actually works for this application.
:jaw:


Another tip: Those rubber bellows seem to adjust after a few hours of heat cycled run time. Keep a screwdriver or socket with you to adjust those stainless bands when you are out on the water. They sometimes start to drip leak and need retightened once more. After that "break-in" period they are good to go.

 

[muc]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

Not sure if I would use any type of petroleum product in this application.
MerCruiser recommends against this, they recommend using dish soap mixed with water in a spray bottle. Use a wire brush to clean the corrosion and flaking paint off of the outside of the metal tubes and spray them and the inside of the rubber tubes with the soapy water. Should slide down far enough for you to rotate the 90 degree tube back into place and slide the rubber tube back up.

 

[stonyloam]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

While you have it apart take a look at your exhaust shutters (#6) to make sure they are in good shape, If they are missing or the rubber is in bad shape it is a good time to replace them.

 

[MarkSee]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

You know what they say... . (Or is it 'fools seldom differ' )
Buy one for me too...

:lol::lol:Had not heard that one before but will come in handy a bunch with my son.......might try it with my wife....once

I'll pick one up for ya; Wednesday night is the next draw......

Mark

 

[natureschild88]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

OK, finally got another crack at it this morning. But first...

My roommate is a mechanical engineer (whoopdee-doo!) and I thought I'd talk over the issue with him when he got home last night. He mentioned that rubber will shrink when cold and expand when exposed to heat. Soooo...

I had to take the rubber back off of the lower exhaust pipe before I could do anything this morning. It was cold, had stiffened up, and was a true pain in the *** to get back off. Once I finally got it off, I put it in a pot of boiling water for 2 minutes, holding it off the bottom of the pan with some tongs so that it would not burn/melt on the metal surface. This made it considerably more pliable.

From there I lubed it HEAVILY with half a bottle of dish soap (the roommates will want to know where all the dish soap went when they come home today). Maybe I didn't have to use that much. Whatever. It worked! I was easily able to slide the tube all the way down the lower exhaust pipe and rolled the elbow back in line with it. The hard part was pulling it back up and on to the elbow. After fighting it bit by bit for about 3 minutes, I finally got it all the way back on. I cannot feel my finger tips as I'm typing this, it definitely took some motivation and grunting.

Thanks for all of the help and ideas everybody. Now to fix that alternator issue so I can take the boat to the Sierra's tomorrow!! (different forum post)

 

[MarkSee]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

My roommate is a mechanical engineer (whoopdee-doo!) and I thought I'd talk over the issue with him

Nice work and you're boatin' again.:whoo:

If you're around a Merc dealer or that West Marine over on Rosecrans one day, look for that Powertune and consider picking up a can.
Don was a real believer in using that product on stubborn rubber parts and made a believer out of me.

My dad was a mechanical engineer back-in-the-day working on booster rockets for the space program........I can still see that in him these many years later when faced with a problem situation.

Mark

 

[natureschild88]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

If you're around a Merc dealer or that West Marine over on Rosecrans one day, look for that Powertune and consider picking up a can.
Don was a real believer in using that product on stubborn rubber parts and made a believer out of me.

Definitely will do, I'm less than 3 miles from that West Marine (I live in Pacific Beach) and will have to stop by there today anyway to replace one of the hose clamps I snapped when buttoning everything back up :facepalm:

My dad was a mechanical engineer back-in-the-day working on booster rockets for the space program........I can still see that in him these many years later when faced with a problem situation.

I hear you, both of my roommates are mechanical engineers and more often than not, one of them will have some sort of helpful information that I can use when I get in a bind.

 

[JASinIL2006]

Re: Replacing EXHAUST TUBE bellow - is there an easier way to do this!?!

Dish soap did it for me when I needed to adjust mine after dropping the engine back in. I was amazed at how much it helped!