Can I disconnect this pipe without flooding???

[dpb]

The engine is an AQAD41.
The pipe is the lower one coming of the exhaust elbow in the general view that I assume carries the raw water to the base of the exhaust pipe where it connects onto the transom shield.
As per the close up picture......which shows the leak.
Whilst it only leaks with the engine running, I am thinking that the pipe must be full of water at rest as it is below the water line.......there for making any attempt at repair risky with the boat in the water........assuming I work out how to get to the fitting in the first place as it is at the bottom of the rear of the engine.
Can anyone confirm this?
The way I see it is that at the moment I have a boat I can use subject to living with the leak (about a gallon per hour when engine running), against it turning into a real pain of a job if I try it now rather than leave it till next lift out.....expecially if the bolt heads snap off when I try turning them!!!!!
Any thoughts??

 

[[2068]]

That lowest fitting is waaay below the waterline, and will cause major flooding if you disconnect it. That same major flooding will happen if it gives up the ghost underway. If it was me, i would lift and fix.

Are you sure it's coming from there, and not the exhaust pipe itself?

Sinking sux

 

[Divemaster1]

Pipe fitting is well below waterline and looking at the bolts, they are not the primary problem, pipe flange is, so new pipe and gasket is probably required. Would be concerned about the bolts as they probably (looks like SS) are quite well "fastened".

Whilst I believe corosion on mild steel is in about a factor 1:10 on steel loss (I can be very wrong here as I am getting old) , the strength of the pipe flange (metal around the bolts) and the other nuts around the sterndrive is what I would be more concerned about, not the bolts holding the pipe in place..

Think you need some TLC down there at some stage, but knowing very little about the materials and margins on Volvo Sterndrives, and their fasteners (Ie' is structural integrity held if you loose 1x bolt?), I would don't want to be alarmist, or pretending ignoring the issue...

Suggest you enlist help from someone with more knowledge (VP or LS1 perhaps..).

 

[oldgit]

Corrosion causing leak.?

Would not go anywhere near that until boat out of water,even trying to nip up bolts could result in bolts shearing.Curious as on my earlier AQD40 engine those pipes were made from stainless whereas yours appear to be cast alloy.I would be soaking that joint in WD40 or similar from now on to aid ease of removal to prevent bolt from snapping and thread remaining in the alloy transom shield.
Simple job if bolt comes out a b****y pain if it does not.
Cannot remember if gasket or "O" ring under union and seem to recall bolt is threaded directly into alloy with no insert.
This a much earlier outdrive than yours but principle is same.You can see the bolt holes that secure pipes to casting at the bottom.

 

[DAKA]

Isnt it the water cooling hose flange that acts as the seal.

It doesnt look standard to me, the pipe and fitting has been modified but I only know 1988 ish.

 

[volvopaul]

Yes you will have water ingress and I'd say it's a sooner than later job, you may also find the shield corroded away behind the pipe where it joins.

 

[dpb]

Thanks for your comments, alot confirming what I feared.
Good idea with the wd40 soaking, and nipping the bolts up was a temptation I resisted, as I am not sure that a sheared bolt could be sorted without taking the engines out for access.
The engines are 89 and the bits seem to match up with the explopded views on one of the suppliers websites as far as I can see.
Other pictures I have suggest that it isnt about to drop off just yet so as this is my first season with the boat, I want to use her a bit more to flush out any other issues that may need adressing during a lift out.
A proper going over of the outdrives is 'scheduled' for next winter anyway, and as you have pointed out this area definately needs attention!
I have invoices for the engines being removed a couple of years ago though it is not possible to see why they did this but I am thinking the joint was disturbed then and maybe not reassembled properly.
Eitherway I will keep an eye on it and definately wont touch it till she is back out of the water!
Thanks

 

[oldgit]

As temp fix,I cleaned all the surfaces with brass brush and emery and then wiped off any grease residue with thinners.Dried area with warm air gun and followed with a dollop of CT1 or similar over the lot.This reduced water to a weep until boat was taken out about month later.
In my case cleaning joint and refitting with sealant sorted problem.

When we did my knackered transom bearing,a simple tripod of scaffolding was rigged with block and chain and engine was merely lifted and moved forward only enough to do required work on transom.
Need not be serious money involved unless of course you want it to

 

[Spi D]

WD40 has a lot of uses. True penetration and rust release is not one, despite the commercials.

Go for something known to penetrate and lube, preferably containing PFTE ('Teflon'). Repeated soaking and time to work (overnight) makes wonders.

 

[PaulGooch]

If it isn't going to be done anytime soon (which could be a mistake, failure here will almost certainly result in a sinking), i wouldn't spray anything with anything. Some rust might be all that's holding back an even bigger leak.