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Removing exhaust riser/elbow to replace leaky gasket-UPDATED

Posted: Fri Nov 05, 2010 1:03 pm
by davescarrs
I have FWC Crusader 350's (454s) in my 1987 10 Meter Int Express. I have some antifreeze leaking from a gasket on my exhaust. I was gonna pull off the riser/elbow (?) and replace gasket. There are four bolts holding the piece on. I backed off the nuts...do I now need to tap the riser off with a mallet or dead blow hammer to seperate the two? Is there more to it then the four bolts?

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Re: Removing exhaust riser/elbow to replace leaky gasket

Posted: Fri Nov 05, 2010 2:47 pm
by rossjo
davescarrs wrote:... There are four bolts holding the piece on. I backed off the nuts...
Do you mean there are 4 studs going through the elbow with nuts on the outside? If so, then yes, you should be able to loosen it with a rubber mallet.

Posted: Fri Nov 05, 2010 10:03 pm
by davescarrs
Yes- 4 studs. I will use a mallet and see what happens. Thanks!!!

Posted: Fri Nov 05, 2010 10:04 pm
by rbcool
GFL on the rubber mallet. I did the identical looking risers on a f-36 last year and had to gently massage them with the bottom of my shoe lol
Don't forget to properly prep the mating surfaces!!!!!!
Ron 8)

Posted: Mon Mar 14, 2011 8:54 pm
by davescarrs
rbcool-

I'm gonna have to spray with some PBR Blaster and heat up to get these things off.

Did you remove to simply replace the leaky gaskets or was it a symptom of another problem? Wondering what the life span is of the manifolds. The engine on the other side is starting to get a little warmer and there is more steam coming out of the exhaust while underway. All the gaskets appear the same way on the other manifolds/exhausts on both engines, but I've never seen anything dripping from the others and the coolant level stays the same.

riser/elbows

Posted: Mon Mar 14, 2011 10:01 pm
by BobCT
Dave,

If you're not sure how old the risers and elbows are,I would replace them. The manifolds are fresh water cooled (anti-freeze) and should be fine.

Some people pull them apart and/or get them boiled....which can done but you've probably read enough posts about "water in the oil", "hydrolocking, etc." and that's where those failures occur. The fact that you're seeing more steam and higher temps means replacement to me. It's not hard at all once you do one, then just repeat three more times.



Bob


P.S. - just noticed that you have engine/hot water heating as well so you have a another "piece" to consider.

Posted: Tue Mar 15, 2011 10:18 pm
by davescarrs
Thanks!!! I'll post what I find.

Posted: Wed Mar 16, 2011 9:37 am
by Stripermann2
I'm with Bob, if you go to the trouble, pull the manifolds and replace the them as well, with new hardware.

Posted: Wed Mar 16, 2011 1:22 pm
by alexander38
+1

Posted: Wed Apr 06, 2011 10:29 am
by davescarrs
Update on original post:

When driving the boat to its winter home I noticed some small drips of antifreeze coming from the gasket area between the freshwater adapter and the manifold (as seen in pics from original post)........

I pounded the riser away from the freshwater adapter then had to pound the freshwater adapter off the studs (thought it would just slide off by hand).

Anyway, everything appears to be in great shape, I expected something to be very wrong after reading horror stories of the water jackets thinning and breaking apart etc. The exhaust manifold looks terrific and on the other side of the riser the elbow looks fine. However, I'm still going to buy a new freshawater adapter/riser/gaskets/and brass nuts and reattach.

The boat is FWC and used in freshwater. It is a 1987, has 350 hours on the 454 (mod 350) Crusaders and everything is original.

Does anyone torque the nuts onto the riser studs down to a certain specification?

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