aq130 copper pipe and close call

pcmpete

Petty Officer 1st Class
Joined
Apr 24, 2009
Messages
328
I took my Aq130c powered boat out at the weekend, everything was going good. Then the temp started to rise to 280 and water was coming from the dog house.
I quickly realized that a cooling pipe/tube had come off, so I had to think quick, do I shut it down and run the risk of it not starting again or race back to the ramp.
I choose to head back to the ramp, while watching the temp and water level rise as the stern of the boat slowly filled with water. :eek:

Got back the ramp with just about 5 inches of the transom above the water line.

After loading the boat back on the trailer and drained half of the lake out of the boat I discovered that the copper pipe that goes into the oil cooler had come out. :(

No wonder why the bilge pump could not keep up, it was fighting a losing battle against the raw-water pump.

So my questions are,
What is the best way to reseal the copper pipe back into the oil cooler so this does not happen again?

Why did the pipe come out in the first place?

Would the 280 degree temp hurt the engine in any way?
The water level was right up over the oil pan, when the water drained out it was a warmer than the lake water, would this help dissipate heat from the engine? (like external cooling)

Why did it come out in the first place?

Any input would be great, as I don't want to go thru that experience again.

P.S. I will be installing two bilge pumps before I take it out again, once bitten, twice sunken boat :D
 

louiss3000

Cadet
Joined
Apr 26, 2010
Messages
20
Re: aq130 copper pipe and close call

The front pipe, or the rear pipe?

Water enters the oil cooler thru the front pipe, and exits the rear, then into the exhaust mainfold. The rear is "trapped" into the cooler in that it bolts to the manifold and cannot move. Note that both caps on the cooler point basically straight up. If you loosen the thru bolt on the cooler, you can be sure the caps are aligned so the tubes go straight in.

The front pipe is also trapped as it is attached to the bottom of the manifold just behind the alternator, then at the front by the short hose section attached to the raw water pump.

Basically, there is no pressure involved, unless the exhaust elbow is clogged, as were mine.

There are rubber seals there where the pipes go into the cooler, Volvo # 418411, put the seal (really a flat o-ring) on the tube, then push it into the cooler. The seal at the top of the rear tube is Volvo #418445.

Simple design, but fairly sturdy...
 

pcmpete

Petty Officer 1st Class
Joined
Apr 24, 2009
Messages
328
Re: aq130 copper pipe and close call

The front pipe, or the rear pipe?

Water enters the oil cooler thru the front pipe, and exits the rear, then into the exhaust mainfold. The rear is "trapped" into the cooler in that it bolts to the manifold and cannot move. Note that both caps on the cooler point basically straight up. If you loosen the thru bolt on the cooler, you can be sure the caps are aligned so the tubes go straight in.

The front pipe is also trapped as it is attached to the bottom of the manifold just behind the alternator, then at the front by the short hose section attached to the raw water pump.

Basically, there is no pressure involved, unless the exhaust elbow is clogged, as were mine.

There are rubber seals there where the pipes go into the cooler, Volvo # 418411, put the seal (really a flat o-ring) on the tube, then push it into the cooler. The seal at the top of the rear tube is Volvo #418445.

Simple design, but fairly sturdy...

It was the front pipe from the raw-water pump, not sure if there is a blockage in the system that allowed pressure to build or it was just time for that seal to give up.
I have a spare seal but don't have any oil cooler seals/o-rings to rod out the cooler, so maybe I will try and backflush the system to see if any crud comes out.
Good tip on the cooler's end caps

Thanks
 

PiratePast40

Lieutenant Commander
Joined
Mar 21, 2009
Messages
1,734
Re: aq130 copper pipe and close call

Glad to hear you made it back to the dock and were able to get the boat out of the water. It's a good idea to pull the starter and check for water. It might turn over the first few times but rust up in about a week. Disassemble and dry out or take it to a shop if there's any water at all in there.

Here's the drawing for the cooling system:http://www.volvopentastore.com/Cooling-System-Induction-And-Exhaust-Manifold/dm/*******.962080568--**********.226094068--store_id.366--view_id.317467
The clamp (#41) is the only thing that holds the pipe in place. I would agree that it sounds like the cooler may be plugged and creating backpressure. Do you have a raw water strainer installed? If not, it would be a good time to get one.

As for the overheating causing problems - won't know until you run it again. Just be careful. Keep a close eye on the oil appearance and level.

By the way - this is another case where posting a problem helps others. I went out and cheked mine to see how the pipe was attached and discovered that the clamp on mine was not attached to the throttle cable bracket! Sorry to hear about what happened but thanks for posting.
 

pcmpete

Petty Officer 1st Class
Joined
Apr 24, 2009
Messages
328
Re: aq130 copper pipe and close call

Glad to hear you made it back to the dock and were able to get the boat out of the water. It's a good idea to pull the starter and check for water. It might turn over the first few times but rust up in about a week. Disassemble and dry out or take it to a shop if there's any water at all in there.

Here's the drawing for the cooling system:http://www.volvopentastore.com/Cooling-System-Induction-And-Exhaust-Manifold/dm/*******.962080568--**********.226094068--store_id.366--view_id.317467
The clamp (#41) is the only thing that holds the pipe in place. I would agree that it sounds like the cooler may be plugged and creating backpressure. Do you have a raw water strainer installed? If not, it would be a good time to get one.

As for the overheating causing problems - won't know until you run it again. Just be careful. Keep a close eye on the oil appearance and level.

By the way - this is another case where posting a problem helps others. I went out and cheked mine to see how the pipe was attached and discovered that the clamp on mine was not attached to the throttle cable bracket! Sorry to hear about what happened but thanks for posting.

Yes I do have a strainer fitted and it was clear. So far the starter turns over everytime I have tried it (touch wood).
Can the oil cooler be successfully cleaned without removing from the block?

I wonder if there is any way of putting a water pressure gauge/alarm in this system. Maybe I am getting paranoid :redface:
 

PiratePast40

Lieutenant Commander
Joined
Mar 21, 2009
Messages
1,734
Re: aq130 copper pipe and close call

You could disconnect the discharge side and run water through it to see if it's plugged. Sounds like louiss3000 has some recent experience and checking the exhaust manifold as well makes sense. Realistically, you'll have to check the cooling system all the way through. Be carefull removing any other copper cooling pipes. You won't like getting them aligned and leakproof if you bend anything.
 
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